Condensing Water Heaters Legislation UK

Condensing water heaters – The UK government announced revisions to the approved document “L” of the Building Regulations of England and Wales, 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 commercial and industrial water heating applications.

Section 6 of the Scottish Building Standards covers energy performance, which means that in Scotland to you must also install condensing water heaters to.

Guidance documents, called the Technical Handbooks in Scotland and the Approved Documents in England and Wales, provide support for the regulations. How to actually attain compliance is explained in the guideline publications.

Energy efficient water heating for domestic and commercial 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 indirect fired 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.

Condensing water heaters – Because the flue gases leaving a condensing water heater are cool, they form a visible mist or plume of water vapour whilst leaving the flue terminal.

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, storage or recirculation hot water system – range is here

• Gas multipoint water heaters   – which are also known as a tankless water heaters / tankless heater
• Condensing water heaters 
• Commercial gas water heaters

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.

Wall mounted industrial electric heaters – 5.3 kW to 22.8 kW output

Wall mounted industrial electric heaters- 3 Phase/ 415 Volt 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 of the commercial premises.

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 with their large heat throw. 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.

An install of our wall mounted electric heaters industrial – these are 3-phase electric fan heaters from Flexiheat UK

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

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

These electric fan space heaters have a fan IP rating of 20 –

The smaller unit has 2 heat settings or outputs – 5.3Kw or 10.8 Kw and the larger has 3 heat settings or outputs – 6.8 kW , 16.3 kW or 22.8 kW.

Download the Electric Industrial Unit Heaters EL BMS Flexiheat Brochure

We also do light industrial heaters or commercial electric fan 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 electric heaters from Flexiheat UK – fan heater wireless

But being more compact fan heaters, these commercial heaters 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 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 – 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.

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 something we can’t do on our commercial heaters mentioned above. 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.

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.