60kW Boiler

60kW Output Gas Boiler

60kw boiler;60kw system boiler;60kw heat only boiler;60kw regular boiler

Our 60kw boiler is a hot water boiler for central heating and will also produce domestic hot water via an indirect cylinder for larger properties or light commercial applications. They are a regular boiler, which are normally wall mounted or can be installed on an optional frame floor standing kit if space is at a premium, when considering your new boiler.

With ERP high efficiencies of 97% full load efficiency and 108% at part load, this is an “A” rating energy efficient boiler, with a compact footprint for this product range.

Condensing boiler – 60 kW

These boilers make use of a method known as condensing, in which the boiler extracts the energy that has been accumulated in the hot exhaust gases before discharging them into the external environment. Because of this, its operating efficiency rating is significantly increased, and it also achieves a greater fuel economy, which results in running costs saving.

A gas condensing boiler is one of the boilers which is the most reliable and efficient for commercial usage. Our boiler features as standard a high efficiency pump integrated within the boiler. This reduces installation labour time and cost.

Commercial boiler or large home heating boiler?

At this boiler output, this boiler may be referred to as a commercial boiler. Some people say anything over a 50kW boiler is a commercial boiler. Any qualified domestic gas engineer, who is gas safe registered can install a natural gas-fired condensing boiler up to 70kW of input. So, is it a commercial boiler or a light commercial boiler or a large domestic boiler – it’s in the eye of the beholder as they say?

60kW System boiler or 60kW Regular boiler

These are 60kW regular boilers, also known as conventional boilers or heat only boilers, these maintain the pressure in the heating system with the assistance of a header tank, also known as a feed (sometimes called a cold water storage cistern) and expansion tank, which is often located in the attic. On the other hand, system boilers make use of a pressurised heating circuit that is fed by water drawn from the mains. System boilers are more common these days as they are sealed heating systems.

You can make our unit into a 60kW system boiler by adding an expansion vessel to the heating system, unfortunately at this size of boiler we don’t have the space within the casing for installation of the expansion vessel.

System boiler fitted with an external expansion vessel; ideal evomax

Stainless steel combustion chamber

Product details and features – careful component selection – for high reliability this product features a stainless steel heat exchanger in our boiler, as it’s the most suitable providing long product life as they provide a higher level of resistance to oxidation and corrosion, whilst light enough in weight at the output rating of 60 kW to be wall mounted / wall hung. Most high quality popular brands also use stainless steel heat exchangers now for reliability, but a few still using an inferior aluminium heat exchanger in their commercial boiler. We offer a 5 year warranty on our heat exchanger.

60 kw boiler;60kw system boiler; gas boiler 60kw; ideal evomax

Stainless steel heat exchanger – lots of space for servicing or boiler repair should it ever be needed

Home heating

When used in larger properties or homes, with normally 20 plus radiators and with multiple bathrooms, a suitable indirect hot water cylinder must be used. We do a full range of these, with sizing details depending the domestic hot water demands – see more on our dedicated webpage – indirect unvented cylinders – for more information on this product range.

Central heating system

This regular boiler can heat a big residential home or commercial facility with the same level of effectiveness. With a high modulation or turndown ratio of 10:1, which ensures great heat load matching to the heating system requirements, you real are getting the best boiler on the UK and Irish markets.

This boiler can be used on an underfloor heating system installation or a traditional radiator heating system installation, and we have cascade options, should you want to use this light commercial boiler in multiples with pipe kit frame etc.

Download the R1K 60 – 60kW gas fired condensing boiler manual from Flexiheat UK

Control and thermostat options for our boilers

The unit has an inbuilt control panel, with simple controls which are easy to use.

A weather sensor is included as standard. It controls the boiler’s output based on the weather outside conditions to make sure it uses the least amount of energy and reduces running costs. This is referred to as weather optimization and compensation.

This unit is also “OpenTherm” compatible which means you can use Nest or Hive controllers to control your boiler from a phone App. Or we do an option called cloud warm.

Opentherm controller Wi-Fi app controlled from Flexiheat UK

Cloud Warm – Wireless Wi-Fi controller – can be app controlled via a phone, iPad or computer.

Natural gas boiler or LPG gas

Our boilers can be supplied in either natural gas or propane gas (commonly known as LPG), we can also supply a conversion gas install kit should you wish to change from natural gas to LPG, or vice versa.

Delivery or Collection

You can purchase your new boiler direct with us, to get the best deal. We can deliver on a small half pallet service – the delivery date might be variable depending on your postcode. For example, a Scottish Highlands, or West Wales postcode can take 2/3 working days – while a “middle England” postcode may only take one working day. Alternatively, you can collect from our local branch at Wimborne, Dorset, England – postcode – BH21 6SZ

60kW Gas Boiler

Should you require any more information or a cost on our 60kW gas fired boiler on the UK and Irish markets, please contact our sales team on 01202 822221 or click here for our email contact form. All of sales are supplied with an inc vat invoice.

9kW Electric Boiler

Electric Boiler 9kw Output

9kw electric boiler for wet central heating water heating;low carbon green energy electric heating

A 9kw electric boiler works just like a gas boiler, just that it’s powered by electricity rather than gas. They benefit from easier installation, as no requirements for flue offers flexible installation location – you can decide where to locate your electric boiler to suit your needs or your customer requirements, unlike a gas system which can be dictated by the flue system requirements of gas or oil boilers.

With no annual gas safety certificate required for electric boilers resulting in lower maintenance costs, and being suitable to installed in customers property for either a retrofit or new installation.

Wet central heating with an electric boiler

These 9kW electric boilers, which provide wet central heating come complete with an integrated “ERP” energy efficient compliant heating pump and an integrated 7 litre expansion vessel, making these electric boilers what is commonly known as a “sealed system boiler” or sealed systems.

High efficiency electric compact or small boiler from Flexiheat UK – 9kw hot water output; electric flow

A compact and small electric boiler – energy efficient home heating electric solution from Flexiheat UK

This means this electric boiler can not only do the heating system, be it an underfloor heating or radiator heating system, but can also heat an indirect cylinder for your domestic hot water requirements if so required.

This allows you to have a “sealed heating system,” meaning that no feed and expansion water tank (i.e., open vented systems) is required in the loft — which can be prone to freezing or bursting, you don’t get this potential problem with sealed systems. It also makes installation much easier and more compact in the property because all the necessary parts are inside the electric boiler casing, such as the factory fitted circulating pump and expansion vessel.

Electric boilers

  • Factory fitted circulating pump – Energy saving ErP compliant pump
  • Heated water temperature output range of up to 80 Degrees C
  • Power surges are avoided with soft start and zero volt switching.
  • No moving parts for long life soft start operation
  • This electric boiler is virtually silent in operation.
  • Space saving unit – this electric boiler is small in size but will deliver a lot of heat – will fit in a standard domestic airing cupboard
  • No Requirement for annual safety certificate for landlords
  • Can be controlled via the nice touch screen panel – with operation front control panel indication of temperature, times etc
  • The boiler can be installed for heating only, or for heating and domestic hot water production, via an indirect hot water storage cylinder
  • Can be used with standard radiators or underfloor heating systems – efficient wet central heating
  • This boiler can use a standard room thermostat ( which must be volt free) , or a “Opentherm” suitable/ compatible room thermostat such as your Hive or Nest type of thermostats, which can allow you to control the electric boiler status via an phone app, iPad or computer
  • Constructed with top brand quality engineered products from the leading manufacturers which ensures long life of the electric boiler
  • No flue system is required for an electric boiler – a nice convenience to have, as it cuts down installation time for the installer and costs for the customer – flexible installation location
  • Has the ability for automatic switching to off peak tariffs

Energy efficient wet central heating system

To ensure maximum efficiency from our unit, our 9kW electric boilers incorporate nine-stage heating modulation, with small increments of 1kW power steps. This unique benefit will modulate the boiler to reduce electricity consumption and running costs, via better heat load matching of the wet central heating system as the thermostatic radiator valves open and close.

FHEL9 Electrical boiler technical details from Flexiheat UK; potterton gold electric boilers

These boilers can be wired either by a 3 Phase 400 Volt electric or 1 Phase 240 Volt electric mains electrical connection- we have highlighted the single phase boiler electrical details in the above data – as it’s the most common electric supply to this boiler size.


The full brochure for our range of units available can be downloaded here –

Flexiheat Brochure For Electric Boiler Range 

Energy efficient domestic hot water heating via a hot water cylinder

Delivery or production of domestic hot water is achieved via pressurised or open vented indirect cylinder, for fast filling baths and to supply multiple tap outlets with hot water supply at the same time – schematically like so

domestic hot water heating with an electric boiler; Potterton gold electric boilers; bathroom showroom; vat add delivery; Potterton gold indirect cylinder

The electric boilers have an automatic system within that operates both the heating and the indirect DHW cylinder

It operates in a switching mode and Domestic Hot Water always has priority

Lower temperatures ( from 25C to 80°C ), can be set and controlled for the heating circuit– and you can use Equithermal control – as our unit is “Opentherm” compatible with various controllers or via our operation front panel indication.

Equithermal control is compensated weather control- the boiler automatically drops the flow temperature relative to the weather conditions – for example on a day when the temperature is 12C outside – and you want 20C inside, the boiler works out that you only require 50C water temperature output to the radiators, and this saves you energy and thus running costs. – more on this in this video

Why is this set up important?

Because you can have two required temperatures – i.e., the heating side of the boiler, may be running underfloor heating – which needs a maximum temperature of 45C, or if the boiler is compensating the flow temperatures to a radiator system, for example – it may have reduced the flow temperature to 50 or 60C – This would not be a high enough temperature to heat the indirect hot water cylinder

For the DHW cylinder, the electric boiler heats up to a higher temperature (usually 75-80°C, to heat the DHW cylinder as quickly as possible) -the automatic control closes the heating circuit and opens the DHW heating circuit, switches on the pump and heating elements and heats to a higher temperature (75-80°C) which heats the DHW cylinder very quickly (100 litres in approx. 10 – 20 minutes! Based on a 15kW)

If you use an unvented mains cold water supply hot water storage cylinder, then you can have a powerful hot water supply delivering mains pressure showering hot water and fast filling baths.

Note – If you require a 9kW electric combi boiler or combination boiler, look at our solution – as a true 9kW electric combi won’t work correctly to produce an adequate flow rate based on the water temperatures we get in the UK and Ireland especially in the winter period – the flow rates as just pathetic and unusable – look our solution here – electric combination boilers

Open vented systems

Pressurised or open vented central heating systems? open vented systems are now old technology when it comes to a wet central heating.

You can use our boilers on an open vent system, but the require minimum head is 8 metres,

But we don’t recommend it as open vented systems allow oxygen ingress into the heating water, which result in corrosion in the system, with standard radiators and some thermostatic radiator valves being manufactured in steel this is not a good idea.

Electric boiler with 9kw Output electric powered

We at Flexiheat UK limited, supply and stock a large range of electric boilers, with our 9kW electric boiler being the best on the UK and Irish markets. Having many benefits such as the best boiler modulation or turndown ratio on the market. Being extremely compact and suitable for use in a house, apartment, mobile home, or flat, along with other types of residential properties.

Please don’t hesitate to contact our sales customer services team on 01202 822221 or use our email contact form via the contact tab above to message us and get the best price. We normally have stock of the electric boiler unit on the shelf, or we can arrange a delivery on a small pallet service, which can either delivered on an overnight delivery service or a 2/3-day delivery service depending on the customer requirement. All our customer invoices are inc vat, as we are vat registered company number GB236 9061 01.

Modular Boilers Commercial

Commercial modular boilers with high energy efficiency

modular boilers commercial with high turn down ratio

Modular boilers commercial with high turndown ratio from Flexiheat UK

Modular boilers commercial – Organizations that require hot water for their commercial space heating, such as schools, hotels and office buildings complexes, frequently employ a modular boiler or a modular boiler system, as they are highly efficient, high performance heating solutions.

Modular boilers are designed to be a high performance and cost-effective alternative to a large single boiler for commercial heating. Each module can be a standalone boiler put in a horizontal arrangement or even as a vertical stack of boiler modules arranged one on top of the other, which gives the boilers an incredibly small footprint, which is great for a boiler room with limited space and allow quick installation.

commercial modular boilers; hot water boilers; water tube boiler; energy saving boiler plant

Vertical mounted modular heating boilers / plant – floor standing gas boilers for commercial buildings

The main advantage of this modular boiler design is that if one module fails, the remaining other modules carry on working normally and continue to provide heating, as the boilers run in a cascade operating configuration.

The net result is increase system security for the heating hydronic systems, as modular systems always provide some level of heating, making them the best solution for commercial applications that cannot afford to be with some level of hot water, whether it be for heating or for the production of domestic hot water.

If the heating engineer incorporates into the design one backup modular boiler to address demand uncertainties, the capacity is available without consuming energy unless demand demands it. Furthermore, the heating system has redundancy. Any present unanticipated demand might be satisfied by installing more modular units if space is provided in the design process for future development.

For retrofit projects, an efficient and flexible approach can be achieved to either an old boiler replacement, with the many benefits of a smooth changeover installation or they can also be installed alongside the existing heating boiler that services the building. The boilers are easier to physically handle during transport and installation.

Reduce carbon footprint in commercial building

These days condensing modular boilers are the standard modular boiler system installed in commercial heating applications, as commercial boilers from 70kW to 400kW have to achieve high energy efficiency, as opposed to the older traditional boiler or conventional boilers that used to be non-condensing hot water boilers.

Condensing boiler technology ensures highly efficient central heating solutions, which is essential in these times of rising energy costs with energy saving being at the top of the HVAC industry and the end users considerations.

Modular boilers work by dividing output capacity, and also increase the heating systems security, with great fuel efficiency as opposed to conventional boiler systems. In short modular boiler systems provide not only a secure but also an efficient approach to essential heating solutions.

Modular boiler systems are not however limited to non domestic buildings or commercial buildings, as they can also be utilised in larger domestic space heating applications as well as opposed to a single boiler install.

gas modular condensing boilers with high turndown ratio;energy saving; hot water climate system; temperature climate control

Modular condensing boilers for large domestic or commercial hot water heating – 75kW, 100kW and 120kW are two boilers in one casing with 20:1 turndown ratio –

Modular boiler systems

What are the advantages of modular boiler systems, and what do modular boilers provide?

Even if one of the modular boilers fails, the remaining boilers in the system can keep the building warm enough. Modular boilers are also far more convenient to service. Access to the boilers is typically easier, and one module can be serviced while the others continue to satisfy the system’s heat demand without causing unplanned downtime to the heating system.

Energy efficiency by better heating load matching

One of the key benefits of using modulating boilers installed in a modular boiler system is to precisely match the heat load profile of the building is of large advantage. The modulating boilers in a multiple boiler system can be regulated in such a way that they modulate together and equal the system demand, thanks to a sequence controller installed in the system.

Each modulating boiler is operated in its most efficient mode, i.e., part-load, by igniting the maximum number of boilers required to match the load, with each running at or near its minimal modulation, making them the ideal modular boilers for commercial hotel or similar heating.

This keeps the system’s operating efficiency at a high level or the most efficient state.

Repair and preventive maintenance

A multiple boiler system enables heating system security, as one of the primary advantages of the modular design is that if one of the boiler modules requires repair or maintenance, the others can continue to operate and provide hot water while the affected boiler module is repaired. That means you won’t have to worry about maintenance or repairs interrupting your operations.

By contrast, if a traditional separate boiler fails, the entire heating system shuts down until the boiler is repaired or replaced in commercial applications.

Turndown ratio

Modular boilers offer some great benefits when compared to conventional systems, with single large boilers. A single large conventional boiler will have a high minimum output level, whereby multiple small units or separate modules, each with their own burner allows the individual boilers to modulate to the heating and hot water system variable levels or requirements which leads to lower energy consumption for these commercial boilers.

Building automation system (BAS) or Building management system (BMS)

Building automation or building management systems are often used as one master controller for commercial building HVAC systems. This means that the modular boilers work under the full control of the building automation system, which monitors the heating demand, and adjusts the heat output and the numbers of modular boilers needed to operate during the heating season.

This results in the space heating being run at the most efficient state, resulting in high efficiency, reduced energy usage and energy operating costs. All our modular boiler systems can be controlled by building automation or management systems, directly via a 0-10V signal.

We also do controllers which are a mini building automation system for the modular boiler system, which will also ensure rotating boilers or heat exchangers within the modular boiler systems.

Heat exchangers

All our gas commercial boilers range and commercial oil condensing boilers range benefit from a reliable and efficient stainless steel heat exchanger.

modular condensing boiler heat exchanger with large turndown ratios; energy efficiency; hot water; direct water heaters

Commercial heating boiler heat exchanger with high modulation rate – manufactured in stainless steel

Hot water boiler system

Modular boiler systems may be set up to sequence boilers in cascade or unison mode. Cascade control starts a boiler at its lowest heating rate, regulates it to its highest rate, and then starts the next boiler to fulfil the system demand. This approach uses the fewest number of boilers to meet the hot water load requirements.

For our gas fired ( natural gas or propane gas options ) modular boilers, please see our dedicated webpage here  – Commercial Gas Boilers 

or for our oil fired option – please see the following webpage – Oil Condensing Boilers 

Commercial boilers – Modular boilers

We at Flexiheat UK, do a full range of modular boilers commercial in various fuel options such as natural gas, propane gas or oil, with the best boiler turndown ratio on the market, that provide reliable heating solutions in a modular or cascade installation. Please don’t hesitate to contact our sales service team on 01202 822221 or use our email contact form via the contact tab above to message us.

Condensing Water Heaters Legislation UK 2022

Energy efficient water heating

Condensing water heaters – The government announced revisions to the approved document “L” of the Building Regulations, which defines the criteria for the energy performance and carbon emissions of new and existing buildings, on December 15, 2021. One of the modifications involves tighter thermal efficiency for domestic hot water systems in commerical and industrial water heating applications.Usually what happens first in the commercial market, often filters down into the domestic market fairly soon after- but there is no news on this as yet.

Energy savings water heaters

Direct­ fire water heaters must have a minimum heat generator seasonal efficiency of 91 percent (gross calorific value, GCV) for natural gas and 92 percent GCV for liquefied petroleum gas (LPG) by June 15 of this year (2022) . For indirect­fired water heaters, the minimum heat generator seasonal efficiency (GCV) for natural gas and LPG is 91 percent. The revised criteria apply to both existing and newly constructed non­ domestic building stock.

In practise, what would the higher criteria imply? It effectively eliminates the possibility of replacing non condensing water heaters with like­ for ­like models in the majority of non-­domestic buildings. Only in extreme cases, where a condensing water heater replacement is declared unsuitable by the building control authority, may a minimum seasonal efficiency of 80 percent for gas or 79 percent for LPG be employed.

Installing our high-efficiency condensing water heaters can result in energy savings of more than 20%.

Conserve energy

The increase in hot water heating efficiency, is part of the government’s plan to attain the UK’s net zero objective by 2050, and it represents a significant step toward more energy­ efficient water heating in non­ domestic buildings.

Direct­ fired water heaters are an efficient and cost­ effective way of delivering huge volumes of hygienic hot water, and hospitals, hotels, and leisure centres, which have a high need for instantaneous hot water, are just a few of the structures that rely on this technology.

Until recently, most manufacturers and suppliers supplied both condensing and non condensing types. Condensing water heaters are capable of capturing and reusing latent heat that would otherwise be lost through the flue gases or hot combustion gases . As a consequence, they are up to 20% more efficient than conventional models. Flexiheat Water Heaters, for example, may attain efficiency of up to 98 percent.

We do a full range, with all of our units having a stainless steel heat exchanger, low nox combustion emissions,better insulation,high energy efficiency, that can be used in a direct, storge or recirculation hot water system – range is here

The stainless steel heat exchangers that are used in our water heaters ensure great thermal efficiency,coupled with our more efficient burners, result in a high level of energy being recovered from the exhaust gases (the same way condensing boilers work) and the net result is less energy is used by the water heater

Energy efficient hot water heaters

The benefit of moving to more efficient condensing units in terms of energy savings is obvious. Many organisations, however, continue to rely on the ability to replace non-condensing water heaters with like­ for ­like models as the present equipment reaches the end of its usable life. Because no substantial work is required, the appliances may be replaced promptly and with minimum disturbance to the building’s regular operations.

While the transition from non­ condensing to condensing water heaters can be relatively simple, some aspects, such as flueing and condensate arrangements, must be evaluated on a project­ by­  project basis. So, our recommendation is to begin working with building owners today to create an asset management programme. They will be adequately educated to prepare ahead to future proof their hot water systems and save energy with regular condition audits and plant asset inspection.

Factors to consider when moving to condensing gas fired water heating

There are two main factors

  1. Condensate drainage –  Unlike non-condensing types, condensing water heaters require an appropriate drainage point to discharge the condensate (the water vapor is cooled via the condensation process and releases the energy – in this process condensate is produced) that forms during normal operation. While a condensate discharge point may be close to the water heater installation, if one is not accessible, another place may need to be found or a soakaway used to accommodate the condensate pipe and discharge – which is normally pvc pipe.
  2. Flue issues – A vertical flue from the plantroom to the roof is usually required for a classic non-condensing water heater. When replacing a non-condensing unit with a condensing water heater,we have options of using either a co-axial flue, split flue or a single flue system with lengths up to 40 metres or lining the existing flue rise may be a possibility, depending on installation standards and restrictions.Alternatively using a horizontal flue that would pass right through an adjacent outside wall are often used , but this is contingent on sufficient wall space and the terminal location – which must comply with the following standards and guidelines for water heaters up to 70kW
  • BS5440: Flues and ventilation for gas appliances with a maximum rated power of 70kW (net); Building Regulations Part J Section: Additional regulations for gas burning appliances with a rated input up to 70kW; IGEM UP 10: Installation of flued gas appliances in industrial and commercial establishments.

By shifting from a reactive to a proactive mindset, they will be able to better prepare for change and budget for future enhancements. Even on the rare instances where exclusions may apply, forethought is essential. Early interaction with building control will be crucial if heating engineers are to be happy with the advice and prevent trouble.
With difficulties come chances. An update will prompt a re-evaluation of the building’s hot water demand. Over the last two years, many businesses will have seen fluctuations in building occupancy. Finally, the revised calculations may indicate that a smaller water heater is now required, resulting in lower initial capital investment and longer­ term operating expenses.

The transition to condensing technology provides designers and end users of hot water heating system with the opportunity to reposition the water heaters to make greater use of space, for example, at a hotel, the original plant room may be turned into an extra bedroom etc.

Budget allowing, there may even be the option of combining low carbon air source heat pumps with condensing water heaters in a hybrid system to reduce carbon footprint even more and achieve or strive for a net zero economy by 2050

Nobody wants buildings to be left in an emergency scenario without hot water, so if your looking at replacing you existing gas fired non condensing hot water heater , with a now compliant to regulations gas fired condensing water heater (tankless water heaters or storage water heater options – all with stainless steel heat exchangers) then we at flexiheat UK are the company to speak to – call our sales team to get a price on 01202 822221 or use our email contact above on the web page.

Hot Horse Shower

Hot horse showers

horse shower uk; hot horse showering; lpg water heater;portable horse shower

A hot horse shower is an absolute necessity on every yard, and the perfect solution for washing horses after exercise or before competition. Our propane gas powered water heaters provide not only instant hot water , and a never ending supply of it, all with the touch of the on button.

The warm water our horse shower unit produces , can not only be used to wash your equine, but also dogs or even humans should the need arise .

Gone are the days of bathing your horse, with a sponge and a bucket of ice cold water. Your horse and you deserve better in our opinion . Warm water, at an accurate water temperature to wash your horse or horses is a demand that most owners want as a minimum these days.

horse; shower;uk;seller portable horse;horse shower portable;portable horse shower

Why use hot water to wash horses

  • Hot water helps activate the shampoo and deliver it to the roots of the hair, allowing it to effectively perform a better job of removing debris and grease form your equine.
  • Hot water results in happier horse, especially when the winter when the temperature is cool or cold
  • Even in the summer, if the horses are really sweaty after activity, it is recommended not to hose the horse with cold water, as this can create complications such as significant blood vessel constriction – it is recommended to use hot water or lukewarm water.
  • These are some of the reasons and benefits of using an instant hot water horse shower.

Equine shower range

We do more than one size of water heater , but our most popular horse shower unit is our SF14 an internal mounted hot water generator, this has no pump, and is a direct flow type of hot water heater, with power output of 24 kW – This will produce 15.82 Litres a minute of 40C hot water temperature in typical summer time running , or 10.54 litres in the winter period.

Thus you could run 2 horse showers continuously in the summer, or one very good horse shower in the winter period. It’s also ErP “A” rated non-condensing low NOx water heater, which can be connected to a propane gas cylinder or propane gas bulk tank.

horse showering hot water system; SF14 water heater; lpg gas;portable horse shower

SF14 Water Heater – Internal – for horse showering supply


Please note this unit has 16mm diameter heat exchanger water ways – the largest we know of on the horse shower market- This diameter ensures very minimal pressure drops, lowers the possibility of clogging, improves thermal efficiency, and makes cleaning easier. This is particularly crucial in locations where the water is hard.

With an easy-to-use control panel to navigate through the menu items such as temperature setting on these high efficiency lpg hot horse showers.

You literally pay for what you get in this product sector, there are a lot of horse showers that are imported from the far east, they are poorly made. If you are considering one, establish their heat exchanger diameter, ask about spares back up, if they are “CE” approved and tested. Our units are manufactured in Europe, are fully CE approved, and have “A” rated ErP efficiency levels – which is important with ever rising energy cost. Pay cheap, pay twice is so relevant to these products.

Water pressure

Please note this SF14 unit requires a minimum water pressure of 0.5 Bar and a maximum water pressure of 6 Bar. So you require a mains water supply to use to the full potential of the water heaters performance.

Instant hot water

Our hot horse shower provides instant hot water on demand, which ensures the lowest energy usage and fuel bills.

Electric powered showers

There are a few electric hot horse showers on the market , which plug into a standard 240 volt – 1 Phase electricity power supply that you have on the riding yard, but these only have a 2kw output capacity, which means that your only getting a 3 ltr per minute water flow rate – simply not good enough for a good horse shower

A standard shower head is 7 Litres per minute flow rate – for example

A typical shower hose set up for our hot horse showers – propane gas or naturalThe only realistic solution for a good horse shower is gas as the fuel -in particular propane gas also known as LPG gas , as this is the most commonly available and easiest gas to get for your horse yard- because it can generate a lot of hot water from relatively small gas bottle or gas bottles, or even a bulk tank if so required.

Portable horse shower ?

Yes, we’ve seen them on the market such as the hippo shower or hippo showers , but whilst a portable horse shower may suit certain horse riding yards or horse and pony owners- they come with some negatives, often the gas ignition system of the hot horse shower is powered by two “D2” batteries which is fine in principle, but it naturally consumes battery power to the point that you need to remember to switch the device off afterwards or you end up with a lot of (expensive) dead batteries.

Other gas powered horse shower systems have a pilot light system for the propane water heater, which can be blown out by any strong gusts of wind.

Horse shower portable

Safety really is an issue with portable horse showers – we believe that the units should be placed inside the stable area or another safe location such as a tack room and the water transported to the horse via a hose – you can easily get hose with spray or shower head set ups that are of the retractable “magic” coil type, which are very neat and tidy – This literally is the case of ” horse to warm water or warm water to the horse ”

portable horse shower;menu items;propane gas;hippo showers;water heaters

Shower portable horse – electric

And when it comes to electric / electrical powered portable horse shower – again – the smaller units – which have a 13 amp plug – are only 2 kW rated – and aren’t powerful enough to produce the hot water you require to have an adequate hot horse shower and often suffer from water pressure problems ( one company / manufacturer actually stipulates that they must be used with a bucket and cannot be used direct from a mains water tap) . I thought we where trying to get away or past from using a bucket ?

Contact us 

If you are interested in our hot horse shower we sell direct, so you can purchase your horse hot water shower water heaters range, which come with a 2 year guarantee, directly from us at Flexiheat UK . We carry stock, so give our customer service team a call for a price for a new equine hot water shower heater.

Wall mounted industrial electric heaters – Industrial fan heater

Industrial wall mounted heaters – electric

Wall mounted industrial electric heaters from Flexiheat UK; commercial heaters; fan heaters wall; industrial fan heaters; electrically heated air; heaters wall mounted

Wall mounted industrial electric heaters from Flexiheat UK

Wall mounted industrial electric heaters are a great heating solution, for the heating requirements for industrial and commercial environments or commercial applications such as factories, warehouses, garages, shops or any large areas that require installation of wall mounted electric heaters to heat either the staff or customers, with comfort heating powered by electricity.

These industrial heaters, are wall mounted fan heaters with the heating capacity, to quickly achieve the heat output and temperature you require. These wall mounted electric heaters benefit from a very low noise level, with intelligent fan control that not only controls the fan speed of these wall mounted heaters, but can adjust the heat output for improved energy efficiency.

These heaters are designed for industrial and heavy commercial use and are built to work correctly in these environments – these are not domestic ones – these are truly industrial units with the many benefits of sturdy construction, industrial grade heating elements which are well suited to larger industrial environments and the heating of them.

Any industrial building or a larger industrial environment that requires an electric wall full heating system should consider our fan heaters, as they have a very low noise level and produce a nice comfort temperature with a great airflow temperature.

In order to produce a warm airflow temperature, the wall mounted heaters fan speed automatically adjusts in relation to the room’s current temperature via intelligent fan control. When the heater model is powered on in a cold room, this prevents these installed wall mounted heaters from blowing cold air into the room. The airflow temperature depends on what heat setting that is selected either manually or automatically by the controller used to quickly achieve the desired room temperature.

Running costs for these wall mounted electric heaters / fan heaters is good as they are 100% energy efficient.

They are also cheaper and easier to install than wall mounted water heated air heaters, as water heaters require both a flow and return pipework, installed on the wall or up in the ceiling area to bring water to the water heaters, as well as other accessories such as pumps. Also, they are cheaper and easier to install than gas fired heaters, as they have no flue pipe system to install through the ceiling or wall.

Wall mounted electric heaters industrial

These wall mounted electric heaters free up valuable floor space, which is often at a premium in factories, warehouses, or a garage making these models particularly suitable for heating these type of environments. These wall heaters are designed for hard work and are ideally suited to large workshops and many other commercial applications resulting in an economical full heating system.

Wall mounted electric heaters industrial from Flexiheat UK; heaters wall mounted; electrically heated air; industrial fan heater; fan heaters; mounted fan heaters

An install of our wall mounted electric heaters industrial from Flexiheat UK

Range options – The “S” for the smaller unit – up to 10.8 kW output or the “L” which is up to 22.8 kW output

Wall or ceiling mounted industrial electric heaters LEO EL form Flexiheat UK; fan heaters wall; heaters wall mounted; industrial fan heater; heating; fan heater wireless

LEO EL Range of industrial electric wall mounted heaters from Flexiheat UK

Download the Electric Industrial Unit Heaters EL BMS Flexiheat Brochure

We also do light industrial heaters or commercial heaters models which are electric wall mounted electric heaters which can be run off a single phase electric supply, however the maximum output this range of commercial heaters is limited to 6kW and the air flow and heat throw range of these fan heaters is somewhat less than our industrial heaters range.

commercial wall hung electric heaters from Flexiheat UK;fan heater wireless; heaters wall mounted; commercial; electrically heated air

Commercial electric heaters from Flexiheat UK – fan heater wireless

But being more compact fan heaters, they are suitable for heating shops or small garages where floor space is at a premium and the rooms air environments do not have too much dust. These heater units can also be supplied for heavy domestic environments as well.

Mounted wall control accessories 

This range of wall mounted electric heaters can be supplied and connected to various control options to produce an even ambient temperature from floor to ceiling and additionally, these mounted industrial fan heaters are equipped with an overheating protection system (both for the heater and fan).Both control options have a thermostatic control and a ventilation only mode which allows the fan to move the ambient temperature air flow around the area served by the heating system, which is useful in the summer periods.

We do a basic control option – the TS controller which has temperature and fan speed switches and thus control of the fan heaters- The fan speed control, and thus the airflow is manual, whilst the temperature and heat control of the heater and room via the thermostat is automatic on these TS units.


ts controller for our wall mounted electric heaters;

TS controller for our wall mounted electric industrial heaters Flexiheat UK



or we do a more advanced control equipment for this heater, which adapts the ec motor on the heater, and adjusts or switches the airflow and heat output levels according to the set temperature of the thermostat in the room. This wall mounted controller is designated the T-Box and is perfect for thermostat for industrial and commercial environments.

T Box controller for Leo Electric unit heaters from Flexiheat UK; electrically heated air; heaters wall mounted; industrial fan heaters

T Box controller for Leo Electric unit heaters – full BMS compatibility

Mounted on the wall or ceiling even

This wall mounted heater range can if so, required be ceiling mounted. Should the installation of the industrial fan heater change or the wall or walls space be required for another purpose, then you can mount these industrial heaters from the ceiling.

electric heaters; hvac system; wall mounted heater electric; heating element; space heater; industrial electric heater wall mounted;

Wall mounting heights for our industrial electric heaters Flexiheat UK

Note for ceiling installation – there must be a minimum of 20 cm from the back of the heater to the ceiling.

Wall Installation 

When wall mounted the maximum height for the smaller “Leo S” model is 3 Metres .The larger heater, the “Leo L” model ,can be wall mounted up to 6 Metres from floor level. Both units can be wall mounted at a lower level if so required.

wall mounted fan heaters

For these wall mounted electric heaters we can also supply a mixing chamber which allows fresh (outside) air to be brought into the space. The air can be heated via the heat exchanger and then directed within the building, depending on the requirements. PTC electric heaters are used to heat the electrically heated air flow, which is subsequently blown within the large areas or room, depending on the needs. There are three air intakes in the mixing chamber: two for recirculated air and one for fresh air. The degree of damper opening may be easily adjusted from 0 to 100 percent.

Our fan heaters wall mounted electric heaters with mixing chamber are equipped with a filter – as standard it’s a coarse 80% (EN ISO 16890-1E) class filters installed on the air inlet. These filters ensures that the majority of coarse debris is filtered out from entering the wall mounted fan heater and its machinery, and wiring accessories.


3 Phase wall mounted industrial heaters

The availability of a 3-phase supply, as with any other electric heater type, greatly expands the potential alternatives as compared to a single phase. Three phase is not a problem in most industrial environments with electrically operated equipment. All of the machinery will run on three-phase power, and three-phase circuits will be installed. The existence of 3 phase not only expands the number of heaters accessible, but also the range of heating output possible, with a 3-phase wall mounted heater capacity typically limited to 22kw within single fan heater. You can use multiple heaters wall mounted to cover the heating requirement. These electric fan heaters have the potential to heat very large industrial and commercial working areas all the way down to shops etc.

Commercial and industrial wall mounted electric heaters

Should you require more information, availability or prices on our wall mounted industrial electric heaters / electric wall mounted industrial heaters then please don’t hesitate to call us / contact our sales team on 01202 822221 or use our email contact form via the contact us tab.

12kw Electric Boiler – Electric Boilers

12kw Electric Boilers

12kw electric boiler; 12 kw electric boilers;

Our 12kW electric boiler can be used for central heating only and to produce domestic hot water as well, via an indirect cylinder. Whether the central heating system has standard radiators or underfloor heating systems, our electric boilers can do either or even both. This is electric heating a wet central heating system

They are the perfect new boiler solution for properties without a natural gas mains gas supply or where flueing requirements prevent the use of a gas or oil boilers, or even solid fuel boilers or electric storage heating.

All of our 12kw electric boilers will modulate their output to the heating requirements received. This reduces the electricity consumption used and, subsequently, the fuel bills and running costs.

With a 12kW output, these electric boilers can be powered by either a single phase 240 Volt electric (the most common electric supply in UK homes) or a three phase 400 Volt electric supply.

If you buy from a supplier or produce your electricity from renewable energy sources- such as wind energy sources or solar electric energy, then you’re heating and hot water system can be zero carbon rated electric energy.

Electric boilers

Advantages / Benefits at a glance:

  • No risk from explosion or carbon monoxide with electric boilers
  • High efficiency – 100% – as no heat is wasted in the combustion process(as there is none) and flue or chimney system unlike natural gas or lpg boilers.
  • Gas boiler restrictions mean that a annual safety certificate is required for a rented property with a gas boiler – this is not the case for wet central heating electric boilers, they do not require a annual safety certificate – that’s right no annual safety certificate is required !
  • Flexible installation location for the electric boiler -the lack of a flue or a chimney and no fuel tanks allows for more flexibility in the installed position, it also reduces the install cost too. Almost silent in operation too.
  • Heating and domestic hot water for your property when used with an indirect cylinder
  • Suitable for use on open vented systems or sealed heating systems. When used in older types of open vented systems, you require a minimum head of 8 mtrs on the boilers. Open vented systems are very rare these days, as a sealed heating system offers so many benefits.
  • Light weight and compact unit – these wall mounted electric boiler units are light weight, and can be installed in many locations – especially useful in smaller properties – flexible installation location with no fuel tanks to install
  • A long life soft start electric boiler system with zero volt switching – reducing maintenance, service and repair 

12kw Output  

  • Which is 12,000 Watts or 40,944 Btu’s of electric output for the wet central heating system.

Energy saving pump with protection against clogging

  • During a lengthy boiler shut-off period, regular spinning (once every 24 hours) keeps it from becoming clogged / blocked.

Very quiet operation

  • Thanks to the silent triac power switches on these 12kw electric model boilers, they are virtually silent, with no moving parts – zero volt switching.

Smart electronic modulating system with step less regulation

  • In low power steps or jumps of 2.5 kW each – the modulating electronic control of this wall mounted heating boiler, will ramp up and down the power steps or levels , to suit the central heating system requirements – be it underfloor heating or standard radiators – this auto heating regulation mode or process ensures reduced energy consumption, as the electric boiler matches the heating output to the demand of the standard radiators or underfloor heating systems, resulting in lower energy bills.

Suitable for Radiators or under floor systems 

  • Long life soft start system – which gently starts the boiler- ensuring that there’s no power surges.

You can use a controller with “OpenTherm +” communication

  • These are your “Nest” or “Siri” type of room thermostat, that can be a wireless or internet room thermostat – that you can control your electric boiler from an app on your phone, pad or computer. Allowing you to control your central heating system on the go.

Or you can use traditional ambient thermostats

Possibility of temperature regulation according to the room or outside temperature

  • Possibility of remote control of the Electric boiler using an SMS message in conjunction with an SMS module ( optional extra)
  • Digital control panel with a clear two-digit LED digital display
  • Safety switch protection – zero volt switching
  • HDO communication – remote switching of the electric supply the boilers to a low rate electricity tariff- very handy if your on an economy 7 type of cheaper tariff electric scheme – saving costs.
  • Possibility to control the water temperature output operation with a 0 – 10 Volt signal
  • Possibility of producing hot water with an external indirect water calorifier / cylinder when using our three-way valves.
  • Top design – with all the components to operate a wet central heating system, with all pipework connections easily accessed as the bottom of the boiler, for easy of installation. The auto air vent is located at the top of the boiler, to ensure it gets the air removed from the electric boilers, quality products are used throughout.
  • Small dimensions of the 12kw output units – greater possibility for installed locations – and lower water content
  • Integrated frost protection – to heat the property, and prevent burst pipes
  • Auto air vent – to remove any air from the units heat up chamber

Heating only or central heating & hot water

Our boilers can be used heating only or central heating & domestic hot water (DHW) when used with an indirect cylinder (which can be an unvented or an open vented systems), you can provide ample amounts of domestic hot water for your bath, or shower, as well as your dish washing needs. We highly recommend an unvented indirect cylinder, due to the benefits of mains pressure DHW.

At 12kw output you can’t get an electric combi boiler to produce an adequate flow rate, or adequate water temperatures , especially in the winter period ,when you require warm water the most. A combi boiler is only really a suitable unit or solution when you have a 3 Phase electric power supply as they require the higher Amps to do the job instantaneously. This is the solution for an electric combi boiler for 15kW or under – using a small indirect cylinder, as with 1 phase / 240 Volt you can’t get an combi boiler to produce enough flow rate to run a bath or shower in the winter period – when you need DHW the most ! quite simply a true electric combi boiler that produces water on demand won’t work at 12kw output or below.


electric boilers for heating and hot water;electric boilers for hot water and central heating; electric hot water boiler system

A diagram showing how an electric central heating boiler is connected to a Domestic Water Cylinder – with stainless steel heat exchanger.

1. These electric boilers have an automatic system in them that operates both the heating and the indirect DHW cylinder

2. It operates in switching mode

3. DHW always has priority

4. For heating it works at “heating” temperature – various temperature (25 to 80°C etc), can be set and controlled – and you can use equithermal room thermostat control –

Equithermal control is compensated weather control- the boiler automatically drops the flow temperature relative to the weather conditions – for example on a day when the temperature is 12C outside – and you want 20C inside, the unit works out that you only require 50C to the radiators, and this saves you energy and thus running costs.

The boiler then automatically switches on the pump and heating elements and regulates to the desired temperature for the heating system.

5. For the DHW cylinder – which can be a , the electric boiler heats up to a higher temperature (usually 75-80°C, to heat the DHW cylinder as quickly as possible) – this automatic control closes the heating circuit and opens the DHW heating circuit, switches on the pump and heating elements and heats to a higher temperature (75-80°C) and heats the DHW cylinder very quickly (100 litres in approx. 10 – 20 minutes!)

6. After the DHW Cylinder is heated, it switches to heating (see “4.”)

Why is this set up important?

Because you can have two required temperatures – i.e., the heating side of the boiler, may be running underfloor heating – which needs a maximum temperature of 45C, of if the electric boiler is compensating the flow temperatures to a radiator system, for example when the thermostatic radiator valves close  – it may have reduced the flow water temperature output to 50 or 60C – This would not be a high enough temperature to heat the indirect DHW cylinder

12kw electric boiler cable size

12 kw electric boiler cable size should be 16 mm2 for use on 1 phase 240Volt electric supply. After installation, all electrical work must be tested in accordance with IEE norms and NICEIC inspection, and a completion certificate must be obtained.

Electric heating company installation

Any electric heating company or a plumber in conjunction with an electrician can install our boilers , there’s nothing special to them and they work with all the standard manufacturer radiators, thermostatic radiator valves, under floor products that standard gas or oil boilers will. Thermostatic radiator valves are used to control individual room temperatures.

More Information / Prices

For more information or prices on our 12kW electric boiler options , then please don’t hesitate to contact our sales team on 01202 822221 or use our email contact form via the contact us tab on the website.

What size electric boiler do I need ? Boiler sizing

what size electric boiler do i need; what size electric boiler do i need calculator

What size electric boiler do I need? It is a question we are often asked. It may be in relation to a new property or replacing existing gas boilers or oil boilers. The following guide will take you through the process and things you need to consider when selecting the correct size boiler. We supply a full range of electric boilers, which are electric system boilers for central heating, be it for underfloor heating and hot water demands, or for radiators and hot water demands (domestic hot water via an indirect cylinder), or just for electric central heating only. So, if you’re looking for a “what size electric boiler do I need calculator”, keep reading.

Sizing an electric boiler for your home

The first part of selecting the correct electric heating boiler for a wet heating system is the heating load, which is expressed as your kW requirement. It doesn’t matter whether you are using radiators or an under-floor heating system – it’s the same for both, as a heating load is a heating load, as they say!

Here’s a quick chart – for properties built after 1990 that have a ceiling height of 2.7 metres, which is the standard, and an insulation value, or U value, of 0.3 – again, this should be the building standard in the 1990’s and onwards.

You can do this in a couple of different ways –

What size electric boiler chart – quick reference

Power Output of Boiler     Heating floor area

4.5 kW                                   ~ 55 m2

7.5 kW                                   ~ 85 m2

9 kW                                     ~ 110 m2

13.5 kW                                ~ 165 m2

15 kW                                   ~ 180 m2

22.5 kW                              ~ 278 m2

24 kW                                 ~ 300 m2

As a general rule, for properties built after the 1990’s, you should allow 1.5 kW for each radiator in your home. For example, if you have eight radiators, you should choose a 12kW electric boiler. This rule may change depending on the height of your ceilings, the type of glazing you have (single or double), and the effectiveness of your property’s insulation.

These rules of thumb are a good basis or guideline, but it’s a good idea to confirm this with a heating engineer before you make a potentially costly error, but this guideline will give you a good understanding of the size of electric boiler you require.


Or should you have an older property / home , than prior to the 1990’s such as an older Victorian type home or a property with different construction, such as stone, or all wood etc, and require a new boiler installation. Then the following is recommended

  1. The cost nothing, but your time method – This is our recommended sizing method, to be absolutely certain, even for homes built after 1990.

Or you could calculate the heat load yourself using the following website – this will tell you the heating load required to heat your home or flat.


Heat Loss calculator is here


2. Consult a plumber or a professional heating engineer –they will be able to do a heat loss calculation for your property and do the boiler installation.

When you have your required output – please see our dedicated webpages on the appropriate boiler you require

Central heating electric boilers


Electric combi boilers

Electric boiler sizing

The electric boiler sizing process is exactly the same as for gas and oil boilers. It all comes down to how well insulated your property is. The higher the insulation level, the lower the electric central heating system output you require and visa versa. It’s all down to the heat loss of your property , as electric boilers work the same as gas boilers or an oil boiler in that they produce a kW output, just that they are powered by electricity.

Frequently asked questions on electric boilers

How much does an electric boiler cost to run?

The easiest way to work out how much an electric boiler will cost to heat your property is to check your annual heat use via your existing energy bill. This will be shown in kilowatt hours for a gas boiler. Multiply the number of kWh by your electricity tariff / , to find your annual electric heating running costs. You may find the amount of kWh used by your electric boiler is lower than that of your gas or oil boiler because it is more efficient, so that figure will be reduced.

1. For Gas boilers

You get last year’s gas bills – and get the kWh’s that the boiler used – then deduct at least 10% off as boilers are at maximum around 90% Gross efficient (electric boilers are 100% efficient) see a full explanation of Gross V Nett efficiency of boilers here – The total quantity of heat that can be produced by burning the fuel either gas or oil and how much of that heat the boiler can deliver inside your home is referred to as gross efficiency, so ultimate gross is what you get out of the boiler as usable heat.

So at the very best, a condensing boiler in a gas boiler or oil boilers are 90% efficient gross – but we’ve seen readings of analysers that had the efficiency as low as 63 % for boilers that were only 15 years old – so there can be some large differences in the real world figures

Get the existing installation checked with a flue gas analyser. It will give a true reading.

So if you have used 1,500 kWh of gas, multiply this by your efficiency figure – let’s just say in this example it is a highly efficient boiler at 90% net.

1,500 x 90% = 1,350 kWh

If the boiler is only 63% efficient, then the revised calculation would be

1,500 x 63% = 945 kWh

When you have this figure multiply it by the price you pay for electric per kWh , as electric boilers are 100% energy efficient– then that’s what it would have cost you for the last years usage. Thus, you are comparing like for like electricity running costs based on the same usage data for gas and oil boiler.

2. For Oil boilers

Same applies as above with regards to efficiency levels etc , but normally kerosene is sold by the litres – Thus, get the litres bought / consumed for the home for the year .

In 1 litre of kerosene, there is 10.35kWh of thermal heat available.

So if some used 500 litres, then they used

500 x 10.35 kWh = 5,175 kWh of energy 

Again, multiply by the efficiency – say 90% at the very best ( if it’s a condensing oil boiler) which can be as low as 60% etc as per the above point for a gas boiler.

5,175 x 90% = 4,657.50 kWh

Then multiply this figure by the price you pay for electricity per kWh, and that’s what it would have cost you for the last year’s usage as compared to an oil boiler. Thus, you are comparing electricity running costs like for like based on the same usage data for your home.

What’s is the largest electric boiler that can be run on 240 volt single phase ?

The largest electric central heating boiler or electric combi boiler you can run of a single phase , 240 volt electric supply is 15kW. Electric boilers tend to be limited by the maximum amps a property has available – normally 100 Amps for a UK property.

What size electric boiler do I need for underfloor heating ?

Exactly the same size as you would require for a radiator system , a “heat loss” is as they say “a heat loss”. Please see the above “what size electric boiler do I need calculator” above on this webpage.

Is my house too big for an electric boiler?

No, electric boilers are available all the way up to 500kW of output, so we can cover any boiler size you would ever require. Your limiting factor will be the amps required to power the electric boiler. After 15kW output electric boiler size , you will require a 3-Phase electrical supply.

Electric boiler size need

Hopefully the above advice on which size electric boiler do i need / what size boiler for heating – which are referred to as an electric system boiler (be it underfloor or radiators heating). These electric boilers can also be coupled up to cylinders for heating domestic hot water for your home hot water services/system.


100kw Boiler – Commercial gas condensing boilers


A 100kw boiler is suitable for large domestic and commercial applications, such as installation of a wet central heating and hot water systems for commercial buildings such as schools, sports and health centres, offices and hotels and communal heating schemes. This particular 100kW boiler is ErP “A” label / class condensing technology gas boiler with efficiency up to 108.83 % in condensing mode and is available in either natural gas or LPG.

100kw boiler; gb162 v2;basket ; installations;inc vat

100kW Gas Boiler – Natural gas or LPG

They are extremely versatile, usually in a wall hung condensing boiler installation although they can be used in a cascade boiler configuration, and we do a full range of time and space saving mounting frames, complete with flow and return headers, gas pipe pipework, low loss header or plate heat exchanger accessories options for primary heating circuit separation.

100kw gas commercial boilers

The unique feature of our condensing commercial boiler, is that they are constructed with two heat exchangers in one boiler casing, if one fails, you still have 50% of your heating demand functioning. You may also service one of the heating units while the other is still functioning, ensuring that your heating water system is never out of commission. This is a significant feature and advantage of these extremely versatile 100 kw wall hung condensing commercial boilers, and unique on the market as far as we know.


Two heat exchangers within our 100-kw gas fired boilers; Worcester gb162;bosch easycontrol ; search; inc vat

Two heat exchangers within our 100 kw gas fired boilers – Flexiheat UK


Servicing the individual boiler heat exchangers, even when used in a common flue heater configuration, is still possible as each heat exchanger has its own flue non return valve installed as standard.

So, what you have is a duty / standby or a duty assist gas boiler set up, but in a one gas boiler set up.

The other huge benefit this gives our 100kw boilers, is the modulation or turn down ratio is 20:1, there’s not another wall hung commercial condensing boiler on the market that has this range performance or ability to match the outputs or heating load required by the system and ensures minimal energy usage.

Best Heat Exchanger – Stainless Steel

Our wall hung condensing 100kw gas fired boilers have a high quality 28mm diameter stainless steel heat exchanger, unlike some of our competition that use an aluminium construction, which many heating engineers regard as inferior. This large diameter ensures the heating water has low pressure drops, guarantees lower risk of clogging, greater thermal heating efficiency, and greater ease of cleaning.


Condensing boiler 100kW – Product technical details

boiler 100kw; Worcester gb162 ; inc vat; cascade

Gas boiler 100kw R1K100 model technical data from Flexiheat UK


Download the Flexiheat Manual for R1K 100 Gas Fired Internal Boiler

28 mm diameter stainless steel water heat exchanger

Large diameter water ways- that prevent clogging and have low pressure drops.

Low Class 6 NOx emissions

Class leading NOx Class 6 emission outputs for boiler 100kw heat output installations.

Control accessories

This gas boiler is fully compatible with BMS systems that are often used in commercial buildings, when installed with our optional 0-10 volt interface card, that fits neatly into the mounting wall boiler.

For installations in large domestic properties, the boiler is fully compatible for connection to an “OpenTherm” controller, such as Nest, Alexa etc, which enables you to control the operation of the heating and hot water functions of the boiler with voice control, an Pad, computer or a phone app.


These commercial gas boilers have compact dimensions, for their heating power output.

R1K100 boiler dimensions; Worcester gb162; inc vat; England

R1K100 model dimensions from Flexiheat UK


Ensures minimal energy usage

The condensing mode of this particular boiler is at its maximum efficiency when the return water of the heating system is under the dew point of the by-products of the gas be used to power the boiler, which for natural gas is around 55C. The lower the return water temperature of the heating system installation, the more the boilers will condense. The boilers maximum output and efficiency performance is achieved when the return water is at 30C for the heating system resulting in minimal energy usage.

Multi boiler cascade system

You can cascade our 100kw boiler, with the ability of adding the various boiler outputs from our range i.e., 50kW, 60kW,75kW, 100kW or 120kW output boilers. We can cascade up to 960kW of installed output, with various combinations of boiler outputs to suit your commercial applications. We go into this in more depth on this webpage – Commercial gas condensing boilers

100 kw gas fired boiler alongside a multi boiler cascade system; Worcester gb162 ;inc vat; bosch easycontrol;cascade

Ultimately this boiler range is extremely versatile, and makes them suitable for everything from large domestic heating to industrial and commercial applications, either as a standalone boiler or used in a multi boiler cascade system either inline or a back to back configuration. They can also produce domestic hot water when used with an indirect hot water cylinder.

More Information / Prices

Four more information or prices on our 100kw boiler / commercial gas boilers in natural gas or LPG, which benefits from condensing technology and is up to 108.83% efficient, then please don’t hesitate to contact our sales team on 01202 822221 or use our email contact form via the contact us tab.

50kW Boiler

50 kW Gas Boiler

50kw boiler; 50 kw system boiler; worcester greenstar 8000; worcester bosch; greenstar 8000 life;

Our 50kW boiler, covers the larger end of the domestic boiler market, and lets you expand into the light commercial boiler requirements that you may have. They are ErP A rated condensing boiler with efficiency up to 108.8 % at 30C return, with key features such as a stainless-steel heat exchanger, fully modulating 10:1 range – which is perfect for heat loading matching ensuring a long and efficient product life cycle and reduced running cost. They are low NOx emission boilers, class 6 – which means they have the least impact on the environment. Available in natural mains gas or LPG. They can be used in a multi boiler cascade system if so required.

50kW system boiler

50kw system boiler; greenstar cdi classic; worcester's quietest boilers; Worcester bosch; worcester greenstar 8000; greenstar 8000 life;

50kw System Boiler from Flexiheat UK – Gas Fired

A system boiler, has a separate unvented cylinder for producing and storing domestic hot water. This ensures that a consistent supply of hot water can be delivered to a large number of showers and taps simultaneously. As a result, a its an excellent choice for a property with multiple bathrooms, that require higher domestic hot flow rate.

System boilers do away with the requirement for a water tank in the loft since they get their water straight from the mains (which is required with a regular boiler). They then heat the water to provide warm water for the cylinder as well as central heating.

You have to install a heating expansion vessel on the installation (by others) which is usual at this output boiler.

System pressure for the hot water is mains water pressure and the stored water gives an excellent flow rate, which overcomes some of the problems with combi boilers.

Because combi boiler they are only really meant to sustain one hot water outlet at a time, they are not well suited to households with a high demand for domestic hot water. Heating performance may well be reduced in high-usage households because combi boilers routinely switch the burner from the heating system to hot water when there is a hot water demand.

This boiler can be matched up to various sized cylinders to suit the home requirements for heating and hot water outputs, with effortless comfort.

However, should your flow rate requirement be under 20 Litres / minute, then a combi boiler could be the best option, as a combi boiler produces hot water on demand – look at our 50kW combi boiler webpage for more information. A combi boiler does both heating and DHW, and is a ErP A rated for reduced running cost.

Key features of our 50 kw gas boiler

Natural Gas or LPG fired

Our efficient boilers are available in natural gas or LPG (Propane) powered units


The boilers output range is 49.19 kW down to 4.83 kW on an 80C/60C heating circuit, or 53.40 kW down to 5.15 kW on 50C/30C heating circuit

50kw gas fired system boiler- R1K50 model - technical data chart - Flexiheat UK; 50kw system boiler; worcester greenstar 8000; worcester bosch; greenstar 8000 life;

50kw gas fired system boiler- R1K50 model – technical data chart – Flexiheat UK

Modulation up to 1:10

For greater efficiency and reduced consumption both in heating and in domestic hot water production, when used with hot water cylinders

Low Class 6 NOx emissions-

NOx is a catch-all term for nitrogen oxides, which primarily include nitric oxide (NO) and nitrogen dioxide gas (NO2), our boilers have the lowest class emissions

System Pressure

Can operate on a heating circuit with a minimum pressure of 0.3 to 3 Bar maximum

Quality components

All boiler sub components are leading brand products and are selected through careful research for a guarantee of quality and reliability over time

An improved display screen

With push control buttons – for easy control of this 50kW gas fired boiler. With fault codes , for fault finding if there’s ever a issue.

Unrivalled quality / price ratio

The best boiler performance at affordable prices

A wall hung boiler, with modern upgraded controls, that make it one of the most efficient and also one of the quietest boilers manufactured on the UK and Irish markets – at only 52 Decibels – which makes a difference with quieter operation.

Heating output –

The boiler power will modulate the heat to the demand of the customers heating system installation, as the boilers output power range will go from from 50kw down to 5kW

Because the heat requirements of a boiler do not remain constant throughout the year owing to changing seasons, it may only be running at 20% of its capacity when it is warmer or at 80% when it is colder, our fully modulating 50kw gas boiler adapts to the heating system requirements, providing higher efficiency and reducing cost through wasted energy consumption.

Heating and Hot Water

Heating and hot water is provided by the boiler, via an indirect cylinder / calorifier – The heating side will heat your radiators or underfloor, whilst providing heat for the coil for the indirect cylinder


We do a range of controls that make your life easier, when it comes to controlling your boiler, from a basic room thermostat / programmer, with push control buttons all the way up to enhanced wireless internet controllers, such as Nest,Hive or bosch easycontrol thermostats, with features that provide you with the ability to regulate and control your heating from any extended location away from your home


We do a full range of flue options, such as horizontal or vertical kits, that ensure installation in the home easy – they are 80 mm / 125 mm outside diameter concentric – thus room sealed

Space required for installation

This 50kw heating boiler range is compact and modern, through award winning innovation in design and operation, it is also one of the quietest boilers to date on the UK and Irish markets -allowing you to locate the unit in any room and keep you cosy in the cold winter months.

50kw Gas boiler - R1K50 Dimensions Flexiheat UK; worcester bosch; worcester greenstar 8000; greenstar 8000 life;

50kw Gas boiler – R1K50 Dimensions Flexiheat UK


Pipework connection detail

Pipework connections for the R1K50 gas boiler; worcester greenstar 8000; worcester bosch; greenstar 8000 life; registered in england; quote;

Pipework connections for the R1K50 ( at the bottom of the unit )


Download the Flexiheat Manual for R1K 50 Gas Fired Boiler

Frequently asked questions

How many radiators can a 50kw boiler run?

The number of radiators a 50kW output boiler can run, will depend on the property. The average sized radiator in a new build home is 1.5kW output, thus newer properties the boiler can run 30 rads to be safe. With older less insulated properties, you’re looking at around 18 to 20 rads, click here for more details

Is a higher kW boiler better?

Boiler are sized to overcome the heat loss from the property ( normally at -5C outside, to give an internal temperature of 20C) in the previous years , you could oversize a boiler, which was not good for efficiency and your fuel bill, but these days the quality end of the market ensures that the boilers are modulating, which means they will operate down to some very low outputs – our 50kW gas boiler will operate down to 4.83kW flow rate, which ensures better heat load matching of the system, with high efficiency and lower running costs , click here for more details.


We normally deliver the boilers on a small pallet service to prevent any damage, for a middle England postcode for example this is around £45, on a 2/3 day delivery date service. Other postcode areas such as the Scottish Highlands / Low Lands, or postcode areas for West Wales and Cornwall as more as it costs us more to send to these areas. For Isle of White, Channel Island, or Isle of man postcode areas, please consult us for more information on a carriage quote.

Gas safe registered engineer

As always, we insist that any gas boilers are installed by a gas safe engineer, not only for the interest of safety, but also for the fact that it’s a legal requirement for the gas installation to be done by a suitable qualified person, so you can sit comfortably, knowing you heating and hot water system is safe. See here for the gas safe website.

Flexiheat UK

Should you require any more information on our 50kw boiler, then our sales team is available (Trading hours -Mon Tue Wed Thu Fri – 8am to 5 pm) to give you a quote and check stock details. Please follow us on Facebook to keep up on our news, reviews etc.