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 underfloor 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.

You can calculate the heat load yourself using the following website – this will tell you the heating load required to heat your home or flat by inputting all your rooms into the calculator and adding the total kW required together to give you the total heat load.

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

or

Electric combi boilers

Combi boilers do both heating and hot water in one unit normally without the need for a hot water cylinder, but there are conditions with regards to the Amps you have available – see the above webpage for more information.

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.

Remember installation costs are lower for electric boilers as the boiler installer does not have to be a gas safe registered engineer or OFTEC registered (for oil) which are required for a gas or oil boiler install.

So, get in touch with us for your electric boiler costs, whether you require an electric system boiler, which works in conjunction with a hot water cylinder for your domestic hot water demand.

And generally, an electric boiler cost less than an equivalent sized gas and oil boilers.

50 kW Gas Boiler

Our 50kW boiler which are a gas boiler powered by either natural gas or propane, are ideally suited to the larger end of the domestic boiler market such as domestic use in larger homes, and lets you expand into the light commercial boiler requirements that you may have.

They are an ErP “A” rated efficiency rating condensing gas boiler with energy efficiency up to 108.8 % at 30C return temperature on the central heating system, 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 of your central heating system.

They are a powerful wall hung boiler and a low NOx emission gas boiler, class 6 with high energy efficiency – which means they have the least impact on the environment as well as lower energy bills and saving money. Available in natural mains gas or LPG. They can be used in a multi boiler cascade system if so required.

These are system boilers , so these boilers require an indirect hot water cylinder  for your domestic hot water demands.

50kW system boiler

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 hot taps simultaneously. As a result, a its an excellent choice for a property with multiple bathrooms, that require a 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 conventional boiler / heat only boiler). They then heat the water to provide warm water for the hot water cylinder as well as central heating.

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

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 that you can have with more than one bathroom properties.

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 hot water cylinders to suit the home requirements for heating and hot water outputs, with effortless comfort and using less fuel compared to an outdated, older inefficient boiler.

The hot water cylinder can also be fitted with an immersion heater for back up water heating which can be powered by a renewable source to help reduced your carbon footprint.

However, should your hot water flow rate requirement be under 20 Litres / minute, then a combi boiler could be the better option, as a combi boiler produces hot water on demand – look at our reliable combi boiler which is a wall hung 50kW combi boiler webpage for more information. A combi boiler does both heating and DHW, and is a ErP “A ” rated energy efficient for reduced running cost and gas bills. A combi boiler will also have less installation costs that a system boiler and water heater ( i.e. a hot water cylinder), but please note combi boilers of this 50 kw size require a good mains water flow rate to supply the DHW output and won’t be the right choice if you haven’t the flow rate required.

Key features of our 50 kw condensing gas boiler

Natural Gas or LPG fired

Main features – our efficient boilers are available in natural gas (mains gas) or LPG (Propane) powered units and are a great central heating boiler replacement or as a new boiler.

Output

The gas boiler central heating 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 heat output on a 50C/30C heating circuit.

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

These wall hung gas boilers can operate on a heating circuit with a minimum pressure of 0.3 to 3 Bar maximum

Quality components

All boiler sub components such as our air separator, pump etc are leading brand products and are selected through careful research for a guarantee of quality and reliability over time.

An improved display screen

Modern design 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 noise level – which makes a difference with quieter operation.

Heating output –

The gas 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 gas 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 gas bills 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

Controls

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

Flue

We do a full range of flue options, such as horizontal or vertical kits, or additional flue lengths in 0.5 or 1 metre extensions 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

Pipework connection detail

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

For easier installation, service, and maintenance, all installer touchpoints have been optimized, with a system pressure gauge located in an easy to read location on the front panel of these gas boilers to show the optimum pressure which gives good peace of mind.

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.

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 high energy efficiency 50kw boiler, then our customer services sales team is available to give you a quote and check stock details. Please follow us on social media to keep up on our news, reviews etc.

LPG combi boilers range – R2KC from Flexiheat UK

There are over four million properties in the United Kingdom that aren’t connected to the mains natural gas network – and this is where LPG boilers, specifically LPG Combi boilers provide a viable solution to power your central heating system and water heating requirements where a natural gas boiler can’t be installed due to no mains supply of gas.

Lpg boilers, whether they be lpg combi boilers or lpg system boilers are an ideal solution to provide heating to the four million homes, that tend to be in rural areas, that are not on the mains gas grid.

There are other options such as electricity, wood, solid fuel, or oil boilers that can be used for off mains gas grid homes, but the most common boiler for these properties is a lpg combi boiler. This is due to the fact that LPG combination boilers not only produce less carbon emissions, thus reducing your home’s carbon footprint, they also save money as they are the most cost effective to purchase and install.

LPG (liquefied petroleum gas or liquid petroleum gas) is also a very efficient fuel too, and has much cleaner fuel emissions than an oil boiler, especially if they are condensing boilers- just like natural gas boilers even though they are both a fossil fuel.

This is why lpg combination boilers are the most popular new boiler for central heating and hot water on the UK market, for properties that have no direct access to the main gas grid.

These lpg combination boilers are the ideal boilers to provide heating to a central heating system be it radiators or an underfloor heating system and also heat water for your domestic hot water requirements – Thus the term  “lpg combi boilers” as they supply both requirements.

How do lpg boilers work? quite simply the same way as a natural gas version – except the key difference – its fuel type is LPG rather than natural mains gas.

LPG Biofuel

BioLPG, also known as biopropane or renewable propane, is an innovative, environmentally friendly alternative to traditional LPG or natural gas. It is renewable and sustainable, and it has the potential to lower your carbon footprint by up to 90%. BioLPG is used in the same way as conventional LPG, making it a ‘drop-in’ option. BioLPG is a low-cost, energy-efficient, and easy alternative to regular LPG gas (Propane), and our combi boilers will run on it.

More information about BioLPG may be found here.

Combination boiler lpg

Combi boilers are designed so you don’t have stored hot water, so there’s no water tank required. They heat the water on demand, which ensures high efficiency and lower heating bills, with the flow of water they can heat is related to the power output of the condensing boiler.

By not having stored hot water in a tank, they are more energy efficient as they are only heating the water that supplies your hot water taps or shower when you require it.

These days all lpg combi boiler types are all manufactured as a condensing boiler, to get the maximum high efficiency from not only the heating system but also the domestic hot water production too. As a new lpg combi boiler will burning fuel at this high efficiency, the result is lower heating bills, due to the condensing function of the lpg combi boiler. This also reduces carbon footprint in a new boiler, when compared to older non condensing oil boilers.

Our condensing lpg boilers achieve efficiencies of 105%, with many benefits such as a lower noise output than the majority of the lpg combi boilers on the UK market, and a patented stainless steel boiler heat exchanger, which is a pipe in pipe design, unlike some of the competition that use an inferior aluminium silicon heat exchanger. Our lpg combi boiler is  ErP rating is “A” for both heating and hot water, to reduce a home’s carbon footprint and carbon emissions.

Gas Boilers – Unique Heat Exchanger

The 12mm diameter internal stainless-steel pipe where domestic hot water is produced, is inside the patented main heat exchanger (28mm diameter). Its total length is 8 meters and this ensures you have a volume (approximately 6 Litres) of “warm water ready to go” as they say. The DHW production is always available and always in condensing operation, resulting in lower energy costs and bills.

This design feature also reduces the chance of scale, something that older technology boilers that use a plate heat exchanger can suffer from. This is incredibly important in hard water areas– as our heat exchanger, with its high velocity and flexing in operation, reduces the ability for scale to build up, and prevents this happening ensuring a long life combination boiler with trouble free operation.

Scale blocking the heat exchanger – older technology heat exchanger systems for DHW production

This unique and clever engineered solution for our heat exchanger system provides many advantages as opposed to the most popular brands of liquid petroleum gas boilers, when you compare Worcester Bosch, Vaillant etc that use a traditional plate heat exchanger system, for the domestic water. This why many consider our lpg combi boiler the best combination boiler on the market when looking for a new lpg boiler.

External Propane combi boilers

We also supply a range of external combination boilers, powered by propane, 24kw ,28kW or 34 kW output, same performance figures as our internal units. These units are fully weatherproofed, and manufactured to IPX5D standards.

External lpg combination boiler

Lpg boiler

A lpg boiler works just like a natural gas or an oil boiler, just that it’s fuelled by liquid petroleum gas or LPG as it’s more commonly known. Whereas natural gas boilers use gas supplied by the main gas grid or mains supply as its also referred too. An Lpg boiler is using fuel supplied either via storage cylinders or a lpg bulk tank. Most lpg boilers, be they combination or system boilers they can be easily converted to mains gas (natural gas) via a simple conversion kit.

Liquid petroleum gas

LPG is an abbreviation for Liquefied Petroleum Gas, which is a mixture of gaseous hydrocarbons derived from natural gas and oil extraction (66 percent) as well as oil refining (34 percent). LPG is still a fossil fuel as such and hence not a true ‘clean’ energy source, but it is a very efficient fuel.

LPG does, however, release less carbon emissions per unit of energy than coal or oil. It emits 81% of the CO2 per kWh produced by oil, 70% of that of coal, and less than 50% of that emitted by coal-generated electricity distributed via the grid. (Source Wikipedia – LPG Gas )

The gas is a colourless odourless liquid when in its stored format. Often, for safety reasons an odorant is added to aid in the detection of any potential leaks.

Lpg cylinders supplying boilers lpg fired

It is either stored in cylinders or a Lpg external storage tank. There are pros and cons of each storage system, and the most popular is a lpg tank storage system, as they use a relatively small space, to store a large amount of the dense liquid form of lpg, which holds a lot of energy efficient fuel.

These days a lpg storage tank comes with devices that monitor the quantity of gas in your tank and automatically inform your provider when it needs to be topped off. So, you never run out of fuel for your central heating system and to heat your hot water requirements.

Lpg combi boilers

The most common models of our huge range of lpg boilers are these –

24kW Lpg combi boiler

This lpg boiler is the smallest of our range of combination boilers. Even though the unit is called the 24kW – it will produce 24.79 kW of output when running at a 50/30°C flow and return temperature, as with all condensing boilers, the lower the return water under the dew point of the flue gases (generally 55C), the more efficient condensing boilers are.

Adversely if running at higher flow and return temperatures for the heating system, say 80/60C, then you’re not going to get the boiler to condense, and lose some energy efficiency, as it’s not recovering the heat from the flue gases. Thus at 80/60C our 24kW combi boiler will produce 22.7 kW of heating output – see the below technical data table for full details.

Our 24kW combination boiler is generally suitable for –

Apartments, flats and smaller 2 Bed houses, that have a maximum of 10 average sized radiators (these days the average radiator size is 1.5kW per rad on a new build) and that have one bathroom.

24kW combi boiler dimensions Flexiheat UK

This lpg combi boiler will fit inside a standard kitchen cupboard, being small and compact as you can see from the above detail.

Fully modulating

This boiler is a fully modulating boiler, which means it varies its output to the heating system requirements, this results in a higher energy efficiency, and reduced energy bills. This also means you can’t really oversize the heating side of the boiler as such, because it adapts to the heating system requirements of your flat, apartments or house. This modulation feature is common across all our range of propane gas boilers and natural gas boilers.

This 24 kW lpg combi boiler will modulate down to 2.9 kW of output.

Making the DHW performance the most looked at element of the boiler –

These days , it’s the domestic hot water (DHW) performance of the boiler , that people usually select the unit on.

First typical flow rates of fixtures found in a property are –

A standard shower head has a hot water demand of 7 or 8 litres a minute

Bath mixer tap – a modern bath tap has an approximate flow rate of 12 Litres /minute

Basin / cloakroom (spray tap type) – 2 litres/minute

Sink taps (standard type) – 4 litres /minute –

So typical winter time performance for the 24kW lpg combi boiler is 11.5 Litres/min

R2C 24kW compact lpg combination boiler – technical data from Flexiheat UK

Download the full manual here for the 24kW version –

Flexiheat R2C 24kW Boiler Manual

28kW Lpg Combination Boiler

Same dimensions and features as our 24kW gas boilers, but with larger outputs – The 28kw designated model will produce 29.04 kW of max central heating output when running at a 50/30°C flow and return or 27.02 kW at 80/60C. It will modulate down to 3.5 kW of output.

28kW Model dimensions

This 28 kW unit will produce 13.7 Litres of DHW at Δt 30°C

R2C 28kW Combination lpg boiler DHW output data

Download the full manual here for the 28kW version –

Flexiheat R2C 28kW Boiler Manual

34kW lpg combination boiler

This 34kW combination boiler lpg fired, is slightly larger than previous units, it will produce 36.19 kW of output when running at a 50/30°C flow and return or 33.35 kW at 80/60C. It will modulate down to 4.1 kW of output.

34kw lpg combination boilers from Flexiheat UK

This 34kW model will produce 16 Litres of DHW at Δt 30°C

R2C 34kw model technical output data

Download the full manual here for the 34kW lpg boiler version –

Flexiheat R2C 34kW Boiler Manual

Warranty 

The standard warranty is for 2 years, but it goes up to 5 years on the heat exchanger if a heating system filter is fitted to the heating circuit to help maintain the efficiency and reliability of the system, which is now required as per the Part L building regulations requirements and also by BS 7593:2019, the code of practise for the preparation, commissioning, and maintenance of domestic heating and cooling water systems.

Quotes

Our prices for our range of boiler white lpg fuelled units, which can be used on a standard radiator heating system, with normal radiators valves or thermostatic radiator valves or underfloor heating systems, with a manifold valve set up.

Propane LPG boiler

For more information, free quote for our recommended price on the best lpg combi boiler range for sale on the UK market, manufactured in high quality stainless steel, then please give our sales team a call on 01202 822221, or use the web site contact form.

LPG Combi Boilers for Caravans

Best LPG combi boiler for a static caravan from Flexiheat UK

Propane or LPG combi boilers when installed in static caravans, are considered to be the “ideal boilers” for satisfying the central heating system (radiators or underfloor heating) and the domestic water heating. That’s why LPG combination boilers are the most common lpg boilers for caravans as a traditional gas supply of natural gas is often not available on static caravan sites.

They offer a more powerful and more efficient heating system for their size and will run at a lower cost to the static caravan owner or user.

They are in essence a lpg heating system boiler and static caravan water heater in one combined unit – so there’s no need for lpg heating boiler and a lpg water heater as two separate appliances these days – a compact liquid petroleum gas combi boiler

LPG (liquid petroleum gas) is a popular alternative to the mains traditional gas supply or oil-based heating systems as it’s safe and efficient and it’s easy to get connected today via either an external fuel storage tank or liquid petroleum gas cylinders. LPG is an effective way for caravan owners to heat and provide hot water for their static caravan, as it’s clean, safe and smokeless.

liquid petroleum gas or LPG as we know it in the UK, is the most commonly used fuel for static caravan boilers for the UK and Ireland, as lots of caravan parks or sites are off the mains gas grid.

LPG boilers are a great alternative to electric heating systems. LPG combination boilers very cheap to run, have maximum efficiency and are easy to install. One type in particular, called a liquid petroleum gas (LPG) or propane combi boiler, is very popular with caravan owners because its low cost of running, maintenance and maximum efficiency. Most LPG combination boilers are very compact, and can be installed in any static caravan. They can also be installed in a holiday home, chalets, holiday flats and apartments, so you do not have to live in a caravan to use a lpg combination boiler.

Best LPG Combi Boiler ?

When looking for a new lpg boiler or lpg combi boiler for a static caravan, there are a two main parts to a lpg combi boiler that we need to look at – the central heating side of the boiler for the static caravan and the lpg water heater side of the unit, as well as high efficiency, to ensure your gas bills are as low as possible for your static caravan.

You’re also looking for a compact lpg combi boiler, as static caravans aren’t always necessarily the roomiest of places, an lpg combination boiler that is small, yet powerful enough to do the water heater demands as well as the central heating system is a benefit.

Dimensions of our compact 24kW LPG combi boiler for caravans, the R2C 24kW from Flexiheat UK

The primary lpg combination boiler for static caravans is a condensing boiler, as these use the liquid petroleum gas to the maximum efficiency, both for the heating and water heater side of the boiler resulting in an efficient heating system for your caravan.

Our most popular static caravan boiler is the 24kW model – which will supply heat up to 23.5 kW of heat output / power and will supply your caravan with domestic hot water at a flow rate of 11.5 litres / min at a temperature rise of 30 Degrees C – this is enough to run a bath in the winter period.

We always quote water flow rates at a temperature rise of 30 Degrees – these are winter time performance figures – because we want you to have a hot bath or shower (an average shower uses 7 or 8 litres / minute) when you need it the most.

Heat exchanger of our caravan combination boiler from Flexiheat UK

The 12mm diameter internal stainless steel pipe where domestic hot water is produced, is inside the patented main heat exchanger (28mm diameter). Its total length is 8 meters and this ensures a large capacity for hot water production. The hot water flow is always available and always in condensing operation, resulting in lower energy costs and bills.

This class leading technology, with the large diameter, also reduces the chance of scale, something that older technology boiler that use a plate heat exchanger can suffer from. This is incredibly important in hard water areas- as our units don’t suffer from this unlike some other leading boiler manufacturers.

LPG static caravan combi boiler technical detail

R2C 24kW Compact lpg combi boiler – Technical data from Flexiheat UK

Download the manual here

R2C 24kW Propane or Natural Gas Combination Boiler for static caravans – Manual

External mounted propane combination option

We also supply an external combi boiler that is weatherproof, this external lpg combi boiler designated the R2K 24 – is a 24kW condensing model, is a little heavier at 37 KG’s – than our internal boiler – thus depending on the weight you caravan wall can take, you can either mount it directly or make a frame from the chassis of the static caravan to support the weight.

External LPG combination boiler for Static caravans from Flexiheat UK

The benefit of having an external compact lpg boiler, that is fully weatherproofed, is that you eliminate (the gladly rare but often fatal) carbon monoxide poisoning risk.

Our boilers can be converted from an LPG (propane) to a natural gas boiler easily, should the need ever arise.

So, if you want supplied a high-quality replacement for your Vaillant or Morco boilers- call us as we have a comprehensive range of LPG combination boilers.

LPG Boiler Controls for Static Caravan

You can control your heating system via the inbuilt control panel or even remotely via an app on your phone, tablet or computer (internet access required), so you can control your boiler from anywhere.

lpg boilers

Our standard lpg combination boilers, which are internally fitted within the caravan, require a flue kit fitted. Our most common flue kit is a co-axial room sealed either horizontal or vertical, which means that all the air for the combustion process is taken from the exterior of the caravan (no windows need to be left open etc).

Horizontal flue kit for the R2C caravan combination boiler from Flexiheat UK

or Vertical

lpg water heaters

If you require just a water heater only, then you just require a lpg water heater, and we do a great range that are ideal high efficiency replacements for older Paloma, Vaillant,Worcester Bosch,Saunier Duval, Rinnai or Morco LPG water heaters.

But a few points to be aware here with regards to lpg water heaters –

There are lots of lpg water heaters on the UK market, that we’ll shall say are of “questionable quality “and also, we question some of the “performance claims”

Our top tips for selecting an lpg water heaters are –

1.Select a good quality manufacture for your lpg water heaters

Preferably from Europe, as by law spare parts have to be available for at least 10 years. Spares (including flue components spares) that aren’t available anymore, means a new water heater in most cases, with the additional expense of installing a new water heater.

2.Ask what country the LPG water heater is manufactured in?

Some are buying product in from the far east, and putting a badge on them – most of these are of very questionable quality to say the least – let alone the spares back up / availability.

3.Make sure your lpg water heaters, have suitable ” ErP” labels supplied

These are minimum requirements these days, to be on the UK and European market

The market for LPG water heaters really is really awash with some poor-quality water heaters, and the old adage of ” you get what you pay for ” or “buy cheap buy twice” really applies to the lpg water heaters market in the UK.

If you’re looking to replace the older Paloma range , Saunier Duval, Bosch, Vaillant, Rinnai or Worcester models, with a water heater range with a great warranty ,for your static caravan, chalets ,holiday home or even a house , then you need to look at this webpage that is dedicated to our dedicated caravan gas water heater  webpage or lpg water heaters  for our full range of water heaters.

Boiler Installation

Any LPG qualified gas fitters or plumbers can fit our lpg combi boiler, they are an easy installation, just connect up to the static caravans heating system and also to the static caravan water heater system.

As we supply plumbers and gas fitters across the country, it is important to use a relevant gas safe engineer, who is qualified to work on and install a lpg combi boiler in a caravan. Use the following website to check – Gas Safe Register

Delivery / Collect Options

We normally have the units available on a 2/3 working day delivery service or a next working day delivery if so required (at extra charge). Or alternatively you can collect from our site. Just let our sales team know your requirements.

Best static caravan boilers / static caravan gas boilers

For more information on the best lpg combi boiler range for a static caravan, residential park homes, chalets or holiday homes or apartments for sale on the UK market, manufactured in high quality stainless steel, then please give our sales team a call on 01202 822221, or use the web site contact form.

LPG Water Heaters / Propane water heater range

LPG (Propane Gas) Water Heaters from Flexiheat UK

Water Heaters LPG Fired

LPG gas water heaters– What are they, and what are the benefits? An LPG (Liquefied Petroleum Gas) water heater is a gas fired water heater that heats domestic hot water instantaneously to multiple points around your home or building. This lpg hot water heater range allow you to connect the energy efficient water heaters to a number of hot water outlets throughout your domestic properties or home or even a commercial building and provide accurate hot water temperature and continuous flow rates.

On demand or continuous flow propane gas water heater?

This type of lpg water heater, provides a simple and proven solution for providing instantaneous domestic hot water on demand, without the need of an indirect cylinder and a propane gas boiler. This liquefied petroleum (LPG for short) gas fired water heaters, which are available in propane (LPG) or as a natural gas water heater are simple, with high energy efficiency and clean combustion. These gas fired water heaters when powered by propane are often called lpg tankless water heaters and provide many benefits with higher energy efficiency than storage gas water heaters.

These gas water heaters are also an energy saving solution to more traditional domestic hot water storage systems, as they only heat the water when its required. These facts have made the lpg flow water heaters not only the customers propane water heater of choice, with great user comfort, to deliver hot water on demand in the most economical and energy-efficient method possible,but also the plumbers / heating installers choice as well.

BioLPG Fuel

BioLPG, additionally referred to as biopropane or renewable propane, is an exciting, ecologically friendly alternative to standard LPG or natural gas. It is both renewable and sustainable, and it may reduce your carbon footprint by up to 90%. BioLPG is identical in its use to conventional LPG so is a ‘drop-in’ solution.BioLPG is inexpensive, energy efficient, and convenient replacement for standard LPG Gas (Propane) and our propane instant hot water heater range will run on this fuel.

Click here for more information on BioLPG

Propane Water Heater? What are the benefits

• High performance mains water pressure to all warm water outlets
• ErP Class “A” energy efficiency for your domestic hot water requirements – Save money and save the environment with our lpg instant water heater range
• LPG tankless heaters -no cylinder required -Tankless lpg water heater systems are far more efficient than storage cylinders and boilers.
• Low NOx or condensing LPG fired water heater – less polluting and better for the environment
• High hot water flow rates of up to 29 litres per minute with a hot water temperature water rise of 33 Degrees C
• We can supply Propane gas or Natural gas fired versions at great prices.
• Internal (indoor lpg water heater) and externally (external lpg water heater) mounted gas fired water heaters are available

External or outside gas fired water heaters from Flexiheat UK

• Modular – Flexibility of usage – multiple heaters can be used to supply greater hot water demands, in cascade.
• These high energy efficiency propane water heaters are suitable for domestic and commercial applications such as domestic properties, cafes, pubs, restaurants, offices or shops
• These propane gas water heaters are simple to install and maintain in any small or limited space location.

LPG DOMESTIC HOT WATER HEATERS

Our range of instantaneous tankless water heaters, are available in either natural gas or LPG Gas. LPG (Liquefied Petroleum Gas) is a gas that exists in a liquefied form, and is a very popular fuel for heating homes, and also in commercial applications such as caravan parks, leisure parks and any other categories where mains gas supply is not available.

The most common LPG (Liquefied Petroleum Gas) gas used for water heaters is propane, as this gas is ideal for outdoor use, as it is not affected by cold weather conditions that we can have in the U.K and Northern Ireland.

This gas has a classification of “G31 Propane”, and can either be stored in larger tanks or mobile cylinders.

Should you wish to run your flow water heaters on (LPG) propane gas, we would recommend a bulk gas tank, however you can run these units of gas cylinders for example – a 47kg propane cylinder maximum continuous off take rate is per hour 32.94 KW, for heaters rated above this input, your LPG hot water heating system will require more than one and thus automatic changeovers valves sets are used or a bulk lpg tank.

For the above reasons, our LPG gas water heaters are very popular in camping and caravan sites, for shower blocks or restaurants and with sports / leisure facilities, such as football and rugby clubs, again for showering facilities, as these water heaters can be used in multiples or in a cascade configuration to give its official name.

CONDENSING OR NON-CONDENSING LPG GAS WATER HEATERS?

For gas fired water heaters to work correctly and condense, the water coming into the contact with the heat exchanger, must be under the dew point of 54°C or lower for propane gas– the maximum incoming cold water temperature, even in the height of summer is 20 Degrees C for the UK, meaning you’re going to have the water heater operating in the condensing mode all year round! and benefit from high energy efficiency.

Thus, this gas fired condensing water heater process will deliver hot water with up to 105% net thermal efficiency, resulting in significant energy savings when compared to conventional non-condensing gas fired water heaters.

Ultimately, condensing propane water heaters just make perfect sense. They are slightly more expensive than non-condensing versions, but that price is warranted with lower running costs and lower impact on the environment.

We do however, produce one unit, which is a non-condensing water heater for the cost conscious, our “SF Low NOx Evolution” model, which is available with a power output of 24 kW. This has been a very popular model for the domestic water heaters/ caravan water heater market, although most consumers can now see the benefit of the condensing hot water heaters, with the UK market moving towards this type.

Our range of instantaneous tankless water heaters, are available in either natural gas or LPG Gas. LPG (Liquefied Petroleum Gas) is a gas that exists in a liquefied form, and is a very popular fuel for heating homes, and also in commercial applications such as caravan parks, leisure parks and any other categories where mains gas is not available. We have many customers who just want to supply just one bathroom or multiple bathrooms – which we can achieve.

The most common LPG (Liquefied Petroleum Gas) gas used for water heaters is propane, as this gas is ideal for outdoor use, as it is not affected by cold weather conditions that we can have in the U.K and Northern Ireland.

This gas has a classification of “G31 Propane”, and can either be stored in larger tanks or mobile cylinders.

Should you wish to run your lpg gas water heater on (LPG) propane gas, we would recommend a bulk gas tank, however you can run these units of gas cylinders for example – a 47kg propane cylinder maximum continuous off take rate is per hour 32.94 KW, for heaters rated above this input, your LPG hot water heating system will require more than one and thus automatic changeovers valves sets are used.

For the above reasons, our LPG gas water heaters are very popular in camping and caravan sites, for shower blocks or restaurants and with sports / leisure facilities, such as football and rugby clubs, again for showering facilities, as these water heaters can be used in multiples or in a cascade configuration to give its official name.

FACTORS TO CONSIDER WHEN SELECTING / SIZING YOUR PROPANE WATER HEATER

There are three important factors to consider when selecting the correct water heater for your requirements.

The standard water temperature for bathing or washing is 40 Degrees C

In essence, it’s just a simple matter of the law of physics – the larger / more powerful the lpg water heater, the greater the flow rate of hot water. This is especially true, when in the winter months, as the mains cold water entering temperatures drops, and this is an important factor to consider in UK.

Thus, the amount of warm water the lpg gas water heater will produce and directly related with the temperature rise that the water heater is required to achieve (more on this in point 2). You basically need to cover the flow rates of your hot water appliances, with your usage patterns.

Flow rates

Kitchen sink taps – 4 to 6 litres per minute

Sink taps – 4 litres per minute – standard type

Basin / cloakroom “spray taps” – 2 litres per minute –

A standard shower head has a hot water demand of 7 or 8 litres a minute,

Bath mixer taps – modern bath taps have an approximate demand rate of 12 Litres per minute

So be adding all of your potential hot water outlets, then applying a diversity factor (a factor that not all of the hot water outlets will be used at the same time) you can calculate your hot water demand

Water Heating – Temperature rise

The temperature rise that the gas water heaters have to achieve. This is also known as T ° variation or delta T which when abbreviated looks like this “ΔT”. Quite simply the amount of hot water produced by any water heater, is directly affected by the temperature rise of the hot water required. An example of this is –

If you set the hot water temperature to 35 ° C and the cold water entering the multipoint gas water heater is 15 ° C, then you have a variation of temperature or delta T of 20 ° C (35 ° Degrees C minus 15 ° Degrees C). Alternatively, if the appliance was set to a desired hot water temperature of 40 ° C, then the temperature rise or delta T would be 25 ° C (40 °- 15°) and thus the flow rate achievable changes.

Mains cold water temperature for the UK

The incoming mains cold water temperature for the UK, for various regions is as follows –

We have two sources of information here –

Mains cold water inlet temperatures for the UK by region Source – Energy Saving Trust – 2008

Or the blue line on the following chart

Please see the blue line for the average mains cold water temperature for the UK over a 12 month period

The above chart shows the coldest water temperature in January at around 5 Degrees C – Source TUV

Please use whatever data your comfortable with

LPG Fired Water Heater Range

We do both a domestic LPG water heater and a commercial heater range, both of which have great temperature control, energy efficiency and capacity.

Unlike a lot of our competitors, we are more than proud to publish our performance data at many different temperature increases, as there may be applications – such as commercial kitchens or other applications which require the water to be produced at higher temperatures, such as industrial hot water systems.

The first and smallest unit is our SF14 propane tankless water heater model which is a 24kW non condensing low NOx model domestic water heaters- this unit benefits from-

• 16mm diameter heat exchanger water ways – the largest we know of on the market (except our condensing lpg units – which are an incredible 28mm in diameter) this size ensures very low pressure drops, guarantees lower risk of clogging, greater thermal energy efficiency, and greater ease of cleaning. – especially important in areas with hard water – and all this with great prices on our gas fired water heaters.
  

  SF14 – LGP tankless water heaters from Flexiheat UK – Internal picture of the domestic hot water heater

   

• Wet chamber copper heat exchanger that prevents thermal inertia
• Reduction of initial water over temperature with low flow rates
• Very low NOx emissions, maximum 50 mg / kWh – better for the environment.

DHW performance for the SF14 unit is –

We class the Red figure – as worst case winter performance , and the Yellow figure as the height of summer performance

SF14 Low NOx water heater hot water performance by Flexiheat UK

The SF14 model are our most popular domestic water heaters and are the perfect solution to the hot water requirements for domestic properties.

Please note due to recent regulation changes the SF14 gas water heaters can only be used in domestic water heating applications for houses or flats etc , if the water heater is in a commercial water heating application, the unit must be a condensing water heater – see this dedicated webpage for further information.

The next range is our condensing lpg instantaneous domestic hot water heaters , which are the most efficient that you can find on the market- there are 3 models in this range, and two different options. All unit will require a condensate drain

SFC range – for direct feed to the hot water outlets (the most common application)

SFK (for dhw recirculation systems) with an in inbuilt pump, the larger 50 water heater model is only available with the inbuilt pump, its up to you whether you use it or not.

The performance is the same for the direct feed and pumped versions of our propane tankless hot water heater.

28kW Propane tankless water heater model performance data

SFC and SFK28 LPG Domestic hot water performance by Flexiheat UK

34kW Propane tankless water heater model performance data

SFC and SFK34 LPG Domestic hot water performance by Flexiheat UK

50kW Propane tankless water heater model performance data

SKF50 LPG Domestic hot water performance Flexiheat UK

Flue Options

We do various flue options, the most common is a co-axial , which takes the combustion air from outside , and flue gas from the device to the outside – making these units room sealed

The most common flue kit is our horizontal co-axial flue kit

Horizontal Flue Kit – Co-axial room sealed by Flexiheat UK

Or the vertical flue kit

Vertical Co-axial flue kit from Flexiheat UK

Using a split flue system, we can achieve flue routes of up to 60 metres for our lpg hot water heater range.

LPG tankless water heater UK

We carry stock, and use a small pallet service to deliver anywhere in UK and Northern Ireland.

For more information, advice or to find /learn more on our energy efficient hot water heating units, which are lpg gas water heaters / propane gas water heaters with indoor or outdoor versions at great prices and quality, or for delivery times, to place an order, get prices then email us at sales@flexiheatuk.com or give our sales team a call on 01202 822221.