12kw electric combi boiler; 12kw electric combination boilers;

12kw Electric Combi Boiler

12kW Electric combi boiler – What are your options?


An 12kW electric combi boiler can be the perfect solution to your heating and hot water demands for a small house or flat. An electric combination boiler does away with the need for stored hot water but with this comes some things you need to be aware of to decide if a combination electric boiler is right for your application.

Here Flexiheat UK, we have a couple of options for your 12kw electric combi boiler requirements. We do a range of 12kw electric combi boilers, that can either be run off a 240 Volt / Single Phase electric supply (the most common household electrical supply voltage for the UK and Ireland) or 415 Volt / Three phase electrical supply. The term “combi” is just an abbreviation for the word “combination” and when used in the context of a 12kw electric combi boiler, this means that the electric boiler will not only do the central heating requirements, but also produce domestic hot water, for your hot water taps within your property or flat.

12kw electric combi boiler; 12kw electric combination boilers;

12 kW Electric Combi or Combination Boilers from Flexiheat UK

12kW Electric Combination Boiler Efficiency & Benefits

None of our 12kW electric combination boilers emit gases or direct pollution when operating as they are not using fuels such as natural gas, LPG gas or Oil and therefore there is no risk of leaks or explosions. All of our electric combination boilers are highly efficient at above 99%, and come with a control panel, and are fitted with the latest ErP low energy rated heating pumps and come with a system expansion vessel. The product benefits and features are –  

  • A fully qualified ErP compliant 12 kW Electric Combination Boiler
  • 50 litres of Domestic Hot Water Storage in the wall mounted version or 80 litres of storage in the floor mounted version 
  • They can be used with a wet underfloor heating system
  • They can be used on a a traditional wet central heating system with radiators
  • They can be used in conjunction with solar heating systems
  • Come with a ErP compliant heating pump
  • Can operate in 2 steps – i.e. half power , or full power output
  • A frost / freezing protection system – If the temperature of the water inside the 12kw electric combi boiler is under 5°C, the pump and heating elements will operate to bringing the water temperature up to 35 Degrees Centigrade, ensuring that the boiler is protected against freezing and any potential damage.

Domestic Hot Water Performance

One of the most important factors in relation to electric combination boilers is their Domestic Hot Water ( sometimes referred to as DHW) performance. With 6 kW of heating elements dedicated to heating the domestic water, which ensure a great recovery time of the stainless-steel water tank, should you use all the water in one go – such as filling a bath. The recovery time of 50 litre tank, (which is used in the wall hung electric boiler) from 10 Degrees C to 60 Degrees C is only 29 minutes – and only 15 minutes from 35 Degrees C to 60 Degrees C. With the floor mounted electric boilers which have an 80-litre tank, the recovery time from 10 Degrees C to 60 Degrees C is only 47 minutes, and only 24 minutes from 35 Degrees C to 60 Degrees C. The temperature of the domestic hot water can be controlled between 35 to 65 degrees centigrade.

ModelPower           (kW)Dimensions  H x W x D   (mm)Weight  Dry     (kg)Domestic Hot Water Storage in Litres
Wall Mounted Model    
FHHSCSM 10/1510kW , 12.5kW or 15kW700 x 600 x 3957150
Floor Mounted Model    
FHHDSC 10/1510kW , 12.5kW or 15kW835 x 600 x 5907680


Kitchen taps – flow rates of between 4 to 6 litres per minute
These days water efficient taps and showers should have the following flow rates –

Showers – flow rates of approximately 8 litres per minute for a standard shower head.

So with 50 litres of storage of domestic hot water , a standard shower uses 65.1 litres of water blended down to 43 Degrees C and lasts for 8.2 minutes at average flow rate of 8 litres . The 50 litre stainless steel DHW tank will provide 83.3 Litres of water , when stored at 60C and blended down to 43C, which is the highest safe showering/bathing water temperature. Ensuring you have nice warm shower, at a good water pressure, up to 7 Bar if required.

Electrical Consumption Details  – including fuse & cable requirements :-

These 12kW electric combi boilers can be wired up either with a single phase 240 volt or a Three phase 400 volt electrical supply, and it is the same detail for both our wall mounted model or floor mounted model.

The following information is relevant when this 12kW electric combination boiler is wired up to a 240 Volt , Single Phase electrical supply –

ModelOutput in kWDraw Current- Amps -1 Phase 240 VoltCable Section in mm2
FHHDCS or M- 10/1510 to 1547 to 68 25

when the unit is wired up using three phase as the electrical supply 

ModelOutput in kWDraw Current- Amps -3 Phase 400 VoltCable Section in mm2
FHHDCS / M- 10/1510 to 153 x 15.9 to 22.8  6


12kW Electric combi boilers for sale UK & Ireland

The full brochure for this 12kw electric combi boiler and the rest of our range as we also do three phase electric versions that go up to 21 kW of heating output, please download our brochure here – 

Download the Flexiheat UK Brochure for 12 kW Electric Combination Boilers

Should you require anymore assistance or information on our 12kW Electric Combi Boiler / 12kW Electric Combination Boilers , please don’t hesitate to contact our sales team on 01202 822221 or click here for our email contact form.