Commercial Combi Boilers – 4 kW to 100 kW Output – Gas Fired

 

Commercial combi boilers or commercial combination boilers, whichever you want to call them, are generally considered to be the United Kingdom’s most popular type of boiler. A commercial combi boiler or combination commercial boiler is a very compact and are highly efficient commercial boilers, that not only supplies all the central heating requirements, but also the hot water for sanitary use, such as bathing or showering, washing up, food preparation, hand washing etc, from many applications such as larger households to commercial applications / commercial premises.

They ensure not only significant savings on installations costs, but also guarantee lower running cost too, making them the best choice from many larger domestic properties or commercial heating requirements, where heating and hot water are required. These boilers are are either wall or floor standing condensing combi boilers ( with a free standing frame kit), that can be fired with either natural gas or LPG ( propane ).This full range of condensing boilers provide high efficiency energy generation with their “Premix Technology” and “Condensing Technology”for heating and hot water production.

COMBINATION COMMERCIAL BOILERS

A combination boiler combines a water heater and central heating boiler in a compact unit, and usually uses a plate heat exchanger to produce the domestic hot water, which when a hot water tap is turned on, the boiler sends the heat produced from the heating side of the boiler, via a control valve to the plate heat exchanger, which then heats up the domestic hot water, until the hot water tap is turned off.

The heat these combi boilers produced can either be utilized by either the central heating system or to the domestic hot water system.

One of the potential issues with a commercial combi boiler is that they require good mains water pressure to achieve good hot water flow rates, and also a large enough plate heat exchanger to achieve this. We classify these units as “a true commercial combination boiler”

If you have a low mains water pressure and flow rate, then it can result in your hot water flowing out at merely a trickle, meaning showering becomes a poor experience, or that filling a bath literally takes for ever.

So, you need to ensure you have the adequate cold water mains flow rate to supply your hot water requirements.

We at Flexiheat UK, have overcome these potential problems by producing a commercial combi boiler, which can be supplied with cold water from either the mains supply , or a cold water storage tank if you have the adequate head / pressure available – the minimum should be at least 1 Bar or 10 Metres of head.

Commercial Gas Combi Boiler -Features and Benefits

1. Compact size – A commercial combination boiler is very compact having a small foot print when compared to the older traditional boiler and indirect cylinder set up found in commercial heating and hot water applications.
2. Reduced installation time and cost – Also because they are mains water fed, there is no need for a cold water storage tank in the roof or loft space, which benefits with installation costs, as less pipework and labour time is required to fit one of these boilers whilst removing the potential of these pipes or water tank freezing in the British winter period – another benefit.
3. Excellent efficiency– These commercial combi boilers are up to 109% efficient, when working on a 30% heating load at 30 Degrees C (typically an underfloor heating system), and are up to 98% efficient at the minimum load when being used on an 80/60 Degrees C heating system (typically an older radiator designed system). Heating a larger home or commercial building is therefore more affordable when compared to conventional non condensing boilers.
4. Adjustable kW output – you can set the commercial boilers to have a maximum power output for example -Then the unit will modulate up and down its output range, to your specified maximum kW output

The 50kW Commercial combi boiler – can be set up to any figure up to 53kW of heat output for the central heating (on a 50/30C flow and return system), thus it can be a 40 kW combi Boiler, a 42 kw combi boiler, a 50kW or even a 52 kW etc, whatever your requirements for these condensing boilers as they can be down rated to suit your requirements. This 50kw combi boiler has its own dedicated webpage – see here for more information – 50kW gas fired combi boiler

The 60 kW Commercial combi boiler – can be set up to any figure up to 62.84 kW of heat output for the central heating (on a 50/30C flow and return system) thus it can be a 60 kW combi Boiler, a 55 kw combi boiler etc

The 70 kW Commercial combi boiler – can be set up to any figure up to 79.35kW of heat output for the central heating (on a 50/30C flow and return system) thus it can be a 60 kW combi Boiler, a 55 kw combi boiler etc.

The 100kW model – anywhere from 5.29 to 106.80 kW heat output at 50/30C flow and return for the for the central heating.

This gives you maximum flexibility, and can also future proof your commercial combi boiler, should you wish to add to your property or premises in the future and require more heating power output for your project requirements.

Commercial gas fired combination boilers

A commercial combination boiler, that utilises a plate heat exchanger to produce the domestic hot water, and therefore has no water storage element – these are wall hung boilers or floor standing boilers for commercial premises.

This commercial boilers range is designated the “RK range” and are available in either natural gas or LPG. These are available in the following sizes

A) A 50kW version – whereby the plate heat exchanger is integral to the casing – This boiler is a modulating boiler with a power range of – 5.29 to 53.40kW output at 50/30C flow and return or 4.83 to 49.19kW at 80/60C with 20.30 litres/min of domestic hot water with a temperature rise of 35 Degrees C.

This 50kW combi boiler has its own dedicated webpage here – 50 kW combi boiler 

B) Or a 60kw, 75kW or 100kW output option – but in these models the plate heat exchanger is mounted directly underneath the boiler above the low loss header ( picture below )

 

The 70kW model, again this commercial boiler is a modulating boiler with a power range of – 3.87 to 79.35 kW heat output at 50/30C flow and return or 3.5 to 72.83 kW at 80/60C with 30 litres/min of domestic hot water with a temperature rise of 35 Degrees C. These can either be wall hung boilers or floor standing boilers when using our frame mounting kit as seen in the picture above.

or the 100kW model-  again this commercial boiler is a modulating boiler with a power range of – 5.29 to 106.80 kW heat output at 50/30C flow and return or 4.83 to 98.37 kW at 80/60C with 40 litres/min of domestic hot water with a temperature rise of 35 Degrees C. These can either be wall hung boilers or floor standing boilers when using our frame mounting kit

Both of these gas commercial combi boilers mentioned above have a modulation ratio of 1:20 for greater efficiency and reduced consumption both in heating and in DHW production. Not only do these units have stainless steel heat exchangers as standard, but they actual have two heat exchangers or boilers as such within one casing, meaning should one fail, you still have 50% of your duty available to you. Another benefit is that you can service one boiler, while the other is working – so there will never be any “down time ” of your heating or hot water system – which is a great feature !!

Commercial Gas Combi Boiler Range

Heating and domestic hot water thermal capacity of  50 kW to 100 kW central heating outputs – wall hung or floor standing boilers with the use of the free standing boiler kit

Environmentally-friendly with lower Class 6 NOx and CO emission rates for  these condensing boilers

Prolonged high performance and high thermal efficiency as the boilers features a stainless-steel heat exchanger with enlarged pipe diameters of 28mm

The comfort and usability of rapid hot water generation via our highly efficient plate heat exchanger these floor standing boilers

A high modulation ratio of up 20:1, means these commercial combi boilers adapt to the heat output required, to suit the site conditions and elements.

Low operational noise levels and heat losses thanks to its configuration with high heat and sound insulation.

The ability to operate with Natural Gas or LPG (Propane Gas)

High efficiency circulation pump with automatic air purge, controlled via a PWM driver.

Simple control with easy-to-use illuminated LCD panel; you can view error codes and boiler information from this panel.

Superior safety features, such as ;
Flame safety control; ionization.
Flue gas temperature control.
Heating circuit overheating safety.
Frost protection.
Low water pressure safety system

Optional room thermostat connection.
Optional remote control.

Hot Water Performance

Our commercial combi boilers uses a plate heat exchanger, that is located just above the low loss central heating header as you can see in the picture below.

 

 

Alternative we do larger plate heat exchangers, that must be mounted sperate to the commercial boiler, on the floor normally, for increased DHW performance.

Below is the hot water performance – i.e., our 75Kw boiler, with a flow and return temperature of 80/60C on the primary side, will produce 2,100 Litres DHW, when raised from 15C to 45C per hour – which equates to 35 Litres per minute.

 

which is very impressive domestic hot water performance indeed, as these combi boilers have a hot water priority system.

Flue options for these combination boilers

The full range of these commercial combination boilers can be flued in various ways. The most common is a co-axial flue system, which makes these commercial combi boilers a room sealed appliance, meaning that the combustion air (the air feeding the burner on the boiler) is brought in from the outside environment to the boiler.

These combi boilers can be flued in a co-axial system –

Horizontally- up to 10 metres in total length, with our 80/125mm co-axial flue system – the use of each 90 ° elbow reducing this length by 0.8 metre, and the use of each 45 ° elbow reducing it by 0.5 metres.

or

Vertically – up to 10 metres in total length, with our 80/125mm co-axial flue system – the use of each 90 ° elbow reducing this length by 0.8 metre, and the use of each 45 ° elbow reducing it by 0.5 metres.

Or these commercial combi boilers can also be flue in a “B23” configuration, whereby the waste flue gas discharge is ensured by a flue system terminating externally from the location of the boiler, whilst the combustion air is absorbed from the location of the boiler. This is sometimes referred to as a conventual flued system.

In a flue gas only single wall flue system these commercial combi boilers can be flued –

Horizontally- up to 30 metres in total length, with the use of 100mm diameter flue – each 90 ° elbow reducing this length by 1.5 metre, and the use of each 45 ° elbow reducing it by 0.8 metres

or

Vertically – up to 25 metres in total length, with the use of 100mm diameter flue – with the use of each 90 ° elbow reducing this length by 1.5 metre, and the use of each 45 ° elbow reducing it by 0.8 metres

Combination Boiler Controls

These commercial combi boilers have an easy to operate control panel, which is an “OpenTherm Plus” protocol control panel, which basically means you can control these commercial combi boilers, via the use of an OpenTherm controller, such as a “nest” or “hive” type or similar. We do our own version called the “Cloudwarm “, which is an OpenTherm controller.

This means you can make your life simpler and control these commercial combination boilers from either your mobile phone (android or apple) your PC or tablet, from anywhere in the world as long as you have internet access. The control panel also has numerous inbuilt features such as –

• Full protection against freezing of the heating and domestic hot water in low ambient temperatures
• Ability to operate according to different heat demands with the variable flow pump control
• Anti-blockage System -The circulation pump is activated automatically once every 24 hours and prevent any blockage
• Low fuel consumption and fixed combustion efficiency thanks to the PWM driver, high modulating fan and high modulating gas valve
• Ability to operate according to different heating system configurations
• Ability to control these commercial combi boilers by Android and IOS operating system
• can be controlled by a BMS system using a 0-10 Volt signal, via an interface card within the boiler.

 

Gas Fired Combi Boiler – Heavy Domestic or Commercial

We often get asked when does the classification of a commercial combi boiler start, well there is no hard and fast rule. We look at this way –
A standard new build house in the UK will use a combination boiler that at most is 30 kW these days
But a domestic gas engineer registered with Gas Safe can work on appliances up to 70 kW net if the gas system has a gas volume less than 0.035m³ with a flow rate up to 6 Metres cubed per hour and the pipework is less than or equal to 35mm in diameter.

Therefore, it is almost better to classify these boilers suitability / applications by description –

Heavy domestic houses / larger properties

These would typically be the following –

2 or 3 Bathroom – then typically our  50kW combination boiler will normally suffice.
3 or more bathrooms – or a large hot water usage property / lifestyle then your looking at the 100kW combination boiler, as normally the central heating requirement for the property would be larger. So, these would typically be larger detached properties, mansions or large country houses.

On the Commercial property applications

You would be look at –

Doctor and dental surgery’s
Schools and colleges
Retail / shop outlets
Commercial and smaller industrial units
Bed and breakfasts establishments / Even smaller hotels

They can be used in any commercial heating application with a radiator or underfloor heating system, or with warm air hot water unit heaters, which we supply for commercial heating of small business units or warehouses.

Commercial boiler – Natural gas or LPG ( Propane ) 

So if you require the best commercial combi boiler for sale on the UK market, that can be used in either commercial premises / applications or even large properties, for commercial heating  then please don’t hesitate to contact us at Flexiheat UK, using the contact us function at the top of this web page, or alternatively give us a call on 01202 822221.Please follow us on social media for all our latest offers.