Electric Central Heating Boilers – 0.5kW to 45kW

Electric central heating boilers – Over 2 million homes in the United Kingdom are at present without a mains gas network supply; also, many older properties have flue restrictions or are listed buildings that prevent the use of a gas or oil boiler on site even if they have a gas supply.

In these situations, an electric boiler can be the ideal solution for your home’s central heating needs. Some benefits of an electric wet central heating system boiler include their relatively small and compact size, allowing them to fit in a kitchen cupboard or under the stairs.

The other great benefit is there’s no flue pipe required, unlike an oil or gas boiler, which requires a flue system to evacuate the products of combustion, i.e., the flue gases. Thus, there is no risk at all of CO₂ poisoning from a faulty flue system or the boiler when you use an electric boiler system.

This requirement for no flue pipe allows you to install your electric heating boiler in the appropriate location to suit your heating power requirements, which is often not the case for traditional flued gas and oil boilers for home heating.

Gas boilers obviously require a gas supply, be it a mains gas/natural gas grid to feed the natural gas boiler, or alternatively gas boilers can also be powered by LPG gas, normally when not on the mains gas pipe, which requires either a bulk storage tank or cylinders – which can be unsightly – making traditional fossil fuel boilers undesirable.

Electric boilers tend to be a great solution in these circumstances and can reduce your carbon footprint/carbon emissions with electric renewable sources, as well as not burning a fossil fuel for your home heating, with electric boiler costs being lower than their fossil fuel counterparts.

This electric boiler range is for a wet central heating system in a domestic property type. If you require an electric boiler to be controlled by a building management system such as ModBus or 0-10 volt control that commercial buildings often use, then you need to use our commercial electric wall hung boilers which have an upgraded control panel, which can do the aforementioned control regimes. You can cascade this range of electric heating boilers with ease, accommodating up to 10 boilers.

Central heating with sustainable energy

As a result of the recently passed legislation regarding boilers, there will be no new gas boilers installed in newly built homes after 2025 to meet climate change targets. Therefore, any new house constructed after 2025 will be equipped with an alternative kind of heating, such as a new boiler or heat pump, for instance. The days of the fossil fuel boiler are numbered, as they say.

Energy-efficient hot water system

A gas boiler, even an a gas condensing boiler has a nett thermal efficiency of 92-94%, when the gas boiler heating circuit temperature is be below the dew point of flue gases (55°C), ideally below 52°C.

Electric boilers are 100% efficient no matter what your central heating systems temperatures are.

Electric Boiler – What are they ?

The most commonly installed boilers either use gas or oil to heat water, whereas electric boilers work by heating the water via an electric element (called an immersion heater) or multiple elements/heaters to heat water – that is the only difference from oil boiler or gas boilers.

They are normally powered by the mains electricity supply. You can also generate your own electric energy via solar PV panels, for example, and help reduce your carbon footprint even further as well as your energy bills.

Should you supply the boiler with electricity generated via renewable energy sources such as wind turbines, tidal or PV solar panels, etc., then you can have a zero carbon footprint, as these forms of energy don’t produce carbon emissions at all and reduce your energy bills. All you need is an electricity supply.

They are energy efficient and popular choice for flats and homes where gas is not an option and oil is either impractical or too expensive.

What size electric heating boiler do I require?

The first part of selecting the correct electric heating boiler is the heating load (kW heating power requirement for the heat loss). We have a full dedicated webpage on how to size an electric boiler here – What size electric boiler do i need ? 

Electric Boilers for Central Heating

 

MN3 electric system boilers

Featuring optional solar PV integration and smart features, the FHMN3 boiler is a flexible electric system boiler that can provide up to 24 kW of output. We also can supply the FHM3 designated version with no expansion vessel, for open vent systems but a minimum 5 metres head (0.5 bar) is required for these boilers to work, again from 2kW to 24kW.

• PV solar panels compatible – Maximise energy produced from PV solar panels to reduce energy bills, reduce reliance on fossil fuels and reduce carbon emissions.

• Outdoor weather sensor and indoor room sensor included as standard for weather compensation – reducing electricity costs for your heating bills and carbon emissions.

• The outputs range from 2 kW to 24 kW and can be adjusted on-site to achieve the required home heating performance.
• These energy efficient electric system boilers have an automatic anti-Legionella feature when using a hot water cylinder.

These boilers may be easily controlled from a distance using an app (*an internet module is required), allowing you to keep tabs on energy use and create personalised heating schedules.

Our range of zero emissions electric boilers for central heating are fully adjustable in heat output to suit your requirements.

Firstly, our 8kW electric boiler

FHMN3-8  This 8kW electric system boiler features an outdoor sensor, a 5-litre expansion vessel, is PV ready, and has an adjustable output range of 2kW, 4kW, 6kW, and 8kW, with options for 230V or 400V 3-phase power supply.

This electric boiler modulates to the following power output steps: 

0.8kW, 0.9kW, 0.9kW,1.3kW, 2kW, 2.6kW, 3.3kW, 4kW, 4.6kW, 5.3kW, 6kW, 6.6kW, 7.3kW, 7.9kW

So yes, this electric central heating system boiler can be set to either 2kW, 4kW, 6kW or 8kW (technically 7.9kW, but close enough to 8kW for us), and the boiler will ramp up and down the above modulation scale depending on what the heating system demands.

This electric boiler serves the requirement for the popular 6kW electric boiler home heating demand that we get.

The next size up boiler is our 14kW electric boiler 

The FHMN3-14 is a 14kW electric system boiler that includes an outdoor sensor, a 5-litre expansion vessel, is PV ready, and has an adjustable output range of 6.9kW, 9.2kW, 11.5kW, or 13.8kW, operating on 1 phase/230 volts only.

This electric boiler modulates according to the following power output steps:: 

0.8kW, 1.5kW, 2.3kW, 3.5kW, 4.6kW, 5.8kW, 6.9kW, 8.1kW, 9.2kW, 10.4kW, 11.5kW, 12.7kW, 13.8kW 

This electric boiler can be set to either 6.9 kW, 9.2 kW , 11.5 kW or 13.8 kW (technically 13.8 kW but close enough to 14 kW for us), and the boiler will ramp up and down the above modulation scale depending on the heating system’s demands.

This electric boiler meets the demand for the frequently requested 12kW electric boiler home heating demand that we get.

and the largest in this range is our 24kW electric boiler

FHMN3-24     A 24kW electric system boiler with outdoor sensor, cascade, 5-litre expansion vessel, PV ready, and 12kW, 16kW, 20kW or 24kW adjustable output range – 400 Volt 3 Phase only.

This 24 kW electric boiler modulates to the following power output steps.: 

1kW, 2kW, 4kW, 6kW, 8kW, 10kW, 12kW, 14kW, 16kW, 18kW, 20kW, 22kW, 24kW

This electric boiler can be set to either 12 kW, 16 kW, 20 kW, or 24 kW, and it will ramp up and down the above modulation scale depending on what the heating system demands.

This is the boiler we use for a 20kW electric boiler or 24kW electric boiler requirements.

 

This boiler range can be used for heating and hot water with an indirect hot water cylinder (storage tank water heater) to produce the DHW. 

This brochure details this above range 

M range electric heating boilers brochure from 2kW to 24kW of output Flexiheat UK 

Manual for this range

M range electric boilers technical and installation manual 2kW to 24kW from Flexiheat UK

With the use of our 3-port valve, you can also heat domestic how water via an indirect hot water cylinder, with these electric boilers. We supply a full range of unvented indirect hot water cylinders in stainless steel so we can supply a full electric heating solution.

Smart phone or tablet app control with Wi-Fi

You can control the “M” series electric boilers using an app on your smartphone or tablet when you have Wi-Fi at the location, which allows you to manage your boiler remotely; for example, you can switch the boiler on when you leave work so that it is warm by the time you get home.

 

Electric system boilers – Things you need to consider and know

Firstly if you don’t know what an system boiler is – we have more detail on this dedicated webpage – Electric system boiler

The biggest and most important issue with electric boilers is not the boilers themselves, it is the power that they require to operate

A typical house will have a single-phase supply whilst a larger house, blocks of flats or commercial building will need or have a three-phase supply.

A UK home typically has a single phase / 240 Volt supply with 100 Amps, this means that all the home electrical appliances, whilst being used simultaneously should not draw over 100 Amps, otherwise the fuse can blow.

So, for example our 15kW electric system boiler at maximum output can consume 66 Amps – should for example a kettle, tumble dryer or an iron (which each can consume 13 Amps each) or 39 Amps in total be used at the same time, then you could exceed your total of 100 Amps and blow your consumer board fuse. Our system monitors the Amps being used for the electrical system – 60 times a second – and will temporarily reduce the boiler output – until the Amps to power the boiler are available again – all automatically – thus you will never exceed your available Amps – and never blow your fuse – guaranteed!

For more information on this accessories system, please see this dedicated web page – maximum current watcher

The Standard Range of Electric Heating Boilers – FHEL series

The Standard Series of Heating Boilers –

The standard range is available in 15kW,22.5kW,30kW,37.5kW and a 45kW Output models. This electric boiler range goes from 2.5kW to 45kW of output, with the following benefits –

• Fluent regulation (boiler output) in low power steps of 2.5 kW for the boilers up to 30kW, and 5 kW for 30 kW to 45kW models for larger homes.
• Option to connect the boilers to an Opentherm+ thermostat or controller e.g., a nest controller etc (control your boiler on the go, from your phone)
• Compensated weather control option for boiler – i.e., control / output according to the outdoor temperature (a great energy saving feature)
• Outputs of up to 15kW, when using a 240 Volt / 1 Phase electrical supply – and up to 45kW when using a 400 Volt / 3 Phase electrical supply
• All of these electric boilers up to 23kW Output have an inbuilt 7 litre expansion vessel inbuilt (i.e., a system boiler), after this size the boilers must use an externally mounted expansion tank dependant on system volume and temperature.
• Option to monitor the maximum current drawn to prevent overloading of the consumer board in the property – this system reduces the input power to the electric boiler automatically – ensuring that your main fuse does not blow.

Please note the following for the for the rated current of these electric boilers – The smaller electric heating boilers up to 15kW, can be wired from either a three phase / 400-volt supply or a single phase 240-volt supply

 

 

Standard Series – Electric Boilers – Technical Data

 

So just to clarify our 30kW electric boiler for example, requires a 3 phase power supply, will use 48 amps per phase at maximum output of 30kW and will modulate in the following power output steps – (also can be set to either) 5,7.5,10,15,17.5,20,25,27.5 or 30kW.

The 38kW electric boiler for example, requires a 3-phase power supply, will use 60 amps per phase at maximum output of 38kW and will modulate in the following power output steps – (also can be set to either) 5,10,12.5,17.5,22.5,25,30,35 or 37.5kW. This is the boiler we use for a 36kw electric boiler requirement.

 

Each boiler is tested – on water circuit tightness and the function of the heating elements and safety checks, before it leaves the factory, and come with a 2 year warranty.

Download the Flexiheat Brochure For Electric Boilers “FHEL” Range

Download the Flexiheat Electric Central Heating Boilers – Installation & User Manual – FHEL Boilers

Advantages of electrical powered electric boilers

Economical

Can be integrated with PV panels to yield further energy savings, or use a cheap energy supplier / energy prices such as economy 7 tariffs, as the units can switch to these supplies automatically, and reduce running costs from these cheaper energy prices

Cheap to buy as electric heating boilers have no gas valves, fans or burners which keeps the cost down as opposed to the average gas boiler. Whilst an oil boiler requires an oil tank to be fitted. Also, an oil tank can also be unsightly and aesthetically pleasing.

No yearly servicing is required

No yearly Gas Safe Certificate / safety checks in relation to rented properties – that gas fired boilers heating systems require.

Running costs can be reduced by using a external temperature sensor so the boiler can optimize and compensate to external weather conditions – further reducing running costs.

Cheaper to install

Installing an electricity powered boiler is simpler than a gas boiler or an oil boiler (no oil tank required for example) and so is quicker and cheaper, also as there are no waste gases an electric heating boiler doesn’t need a flue/ chimney system so the installation costs will be less.

You do not require an external wall when installing electric boilers

Any competent heating engineer can fit an electric boiler and boiler installation costs are lower as compared to a gas boiler. Most heating engineers work or partner with an electrician and work with each other to deliver complete boiler installations

High efficiency

As electric boilers don’t need to burn fossil fuels to produce heat, they don’t lose energy through waste gases or flues. In many cases this results in efficiency rates of 100% compared to 80 – 90% for most gas and oil boilers.

Quiet

Electric boilers are almost completely silent in operation

Light and compact

They lack waste gases and thus any flue / chimney means the unit is much more compact and lighter, ensuring you have more flexibility about where in the property you have it installed. This makes them much more versatile in terms of where they can be placed in the property. Most electric boilers are small in dimensions.

Easier to maintain

No annual landlord gas safety certificate or safety checks are required.

Unlike gas and oil boilers, electric boilers don’t need annual servicing to keep them functioning thus reducing running costs and lower maintenance costs.

Safety

No gas leaks to worry about.

No carbon monoxide leak threat to the people within the property.

Totally safe when the boilers are protected by RCD & MCB

No condensate pipes to freeze up

Can be used with radiators and / or underfloor heating systems

Electric boiler costs

Electric boilers are 100% efficient no matter what your central heating systems temperatures are and are a perfect drop-in replacement for an existing central heating system or a new system. Whereby air source heat pumps drop in efficiency as the external air gets colder, an electric boiler works just like a kettle works with heating elements and unlike heat pumps they are not affected by external air temperature.

Electric boilers for hot water and central heating

By using the heating electric boiler in conjunction with an indirect domestic hot water cylinder, then you can supply plentiful amounts of Domestic Hot Water for your bathing, be it showering or filling a bath and washing up requirements.

This hot water system ensures that the electric boiler does both your heating system and domestic hot water – the wet central electric heating system, be it radiators, under floor or a mixture of both and the domestic hot water via indirect cylinders. In these circumstances the electric boilers are referred to as a system boiler.

An electrical powered boiler can be used as either a “back up” or a “top up” heater for a solar heating system.

Using your appropriate size electric boiler in conjunction with solar water heating to reduce your reliance on bought in electricity or reduce your electricity costs.

 

Gas boiler

Unlike gas fired boilers on a mains gas supply or an LPG supply, electric boilers don’t release waste gases as no fossil fuels are being burnt when operating – thus have a lower carbon footprint.

Electric combi boiler

Electric combi boilers supply both heating and instant hot water in one combined unit, providing central heating and domestic hot water via a heat exchanger. The instant hot water is heated directly from the cold water mains water supply with an electric combi boiler.

Electric combi boilers tend to be limited as to the amount of domestic hot water (DHW) they can produce instantly; therefore, we always recommend using an indirect hot water calorifier for the domestic hot water, especially if the property has a bath fitted as well as a shower.

We do an electric combi boiler range, but as a general rule after 15 kW output a combi boiler will work and produce hot water on demand, but at this output and above (we go all the way up to 40 kW in our electric combi series), require a 3-phase electric supply.

Below 15 kW, which can be run off a single-phase supply, basically an electric combi boiler doesn’t produce enough warm water to satisfy most DHW demands, but we do have a solution; please see our dedicated electric combi boiler webpage for more info on how we overcome this

Electric boilers for sale UK & Ireland

Should you require anymore assistance or information on the best electric heating boiler / electric central heating boilers on the UK and Irish markets, please contact our sales team on 01202 822221 or click here for our email contact form.