9kW Electric Boiler

Electric Boiler 9kw Output

9kw electric boiler for wet central heating water heating;low carbon green energy electric heating

A 9kw electric boiler works just like a gas boiler, just that it’s powered by electricity rather than gas. They benefit from easier installation, as no requirements for flue offers flexible installation location – you can decide where to locate your electric boiler to suit your needs or your customer requirements, unlike a gas system which can be dictated by the flue system requirements of gas or oil boilers.

With no annual gas safety certificate required for electric boilers resulting in lower maintenance costs, and being suitable to installed in customers property for either a retrofit or new installation.

Wet central heating with an electric boiler

These 9kW electric boilers, which provide wet central heating come complete with an integrated “ERP” energy efficient compliant heating pump and an integrated 7 litre expansion vessel, making these electric boilers what is commonly known as a “sealed system boiler” or sealed systems.

High efficiency electric compact or small boiler from Flexiheat UK – 9kw hot water output; electric flow boiler with only a cold water supply needed

A compact and small electric boiler – energy efficient home heating electric solution from Flexiheat UK

This means this electric boiler can not only do the heating system, be it an underfloor heating or radiator heating system, but can also heat an indirect cylinder for your domestic hot water requirements if so required.

This allows you to have a “sealed heating system,” meaning that no feed and expansion water tank (i.e., open vented systems) is required in the loft — which can be prone to freezing or bursting, you don’t get this potential problem with sealed systems. It also makes installation much easier and more compact in the property because all the necessary parts are inside the electric boiler casing, such as the factory fitted circulating pump and expansion vessel.

Electric boilers

  • Factory fitted circulating pump – Energy saving ErP compliant pump – quality products
  • Heated water temperature output range of up to 80 Degrees C operating temperature
  • Power surges are avoided with soft start and zero volt switching.
  • 9 stage heating – this electric boiler 9kw output will ramp up and down to the heating demands in small 1Kw steps or stages – closely matching the requirements of the system and thus reducing electricity consumption
  • Electric system boiler outputs all the way from 1kW to 9kW for a wet central heating system, i.e. underfloor heating or standard radiators and domestic hot water purposes via an indirect cylinder
  • No moving parts for long life soft start operation
  • This electric boiler is virtually silent in operation.
  • Fitted with an auto air vent to eliminate air from the heating system
  • Space saving unit – this electric boiler is small in size but will deliver a lot of heat – will fit in a standard domestic airing cupboard
  • No Requirement for annual safety certificate for landlords and no fuel tanks required -reducing maintenance costs
  • Can be controlled via the nice touch screen panel – with operation front control panel indication of temperature, times etc
  • The boiler can be installed for heating only, or for heating and domestic hot water production, via an indirect hot water storage cylinder
  • Can be used with standard radiators or underfloor heating systems – efficient wet central heating
  • This boiler can use a standard room thermostat ( which must be volt free) , or a “Opentherm” suitable/ compatible room thermostat such as your Hive or Nest type of thermostats, which can allow you to control the electric boiler status via an phone app, iPad or computer and reduce electricity consumption and running costs with weather optimization and compensation that Opentherm intelligent controllers do.
  • Constructed with top brand quality engineered products from the leading manufacturers which ensures long life of the electric boiler
  • No flue system is required for an electric boiler – a nice convenience to have, as it cuts down installation time for the installer and costs for the customer – flexible installation location – annual safety certificate
  • Has the ability for automatic switching to off peak tariffs
  • Product code – FHEL9 – Single phase electric system boiler ( can all be run on a 3 phase supply to)

Energy efficient wet central heating system

To ensure maximum efficiency from our unit, our 9kW electric boiler incorporates nine-stage heating modulation, with small increments of 1kW power steps. This unique benefit will modulate the boiler to reduce electricity consumption and running costs, via better heat load matching of the central heating system as the thermostatic radiator valves open and close or in the case of underfloor heating systems control.

FHEL9 Electrical boiler technical details from Flexiheat UK; potterton gold electric boilers

These boilers can be wired either by a 3 Phase 400 Volt electric or 1 Phase 240 Volt electric mains electrical connection- we have highlighted the single phase boiler electrical details in the above data – as it’s the most common electric supply to this boiler size.


The full brochure for our range of units available can be downloaded here –

Flexiheat Brochure For Electric Boiler Range 

Energy efficient domestic hot water heating via a hot water cylinder

Delivery or production of domestic hot water is achieved via pressurised or open vented indirect cylinder, for fast filling baths and to supply multiple tap outlets with hot water supply at the same time – schematically like so

domestic hot water heating with an electric boiler; Potterton gold electric boilers; bathroom showroom; vat add delivery; Potterton gold indirect cylinder

The boilers have an automatic system within that operates both the heating and the indirect DHW cylinder

It operates in a switching mode and Domestic Hot Water always has priority

Lower temperatures ( from 25C to 80°C ), can be set and controlled for the heating circuit– and you can use Equithermal control – as our unit is “Opentherm” compatible with various controllers or via our operation front panel indication.

Equithermal control is compensated weather control- the boiler automatically drops the flow temperature relative to the weather conditions – for example on a day when the temperature is 12C outside – and you want 20C inside, the boiler works out that you only require 50C water temperature output to the radiators, and this saves you energy and thus running costs. – more on this in this video

Why is this set up important?

Because you can have two required temperatures – i.e., the heating side of the boiler, may be running underfloor heating – which needs a maximum temperature of 45C, or if the boiler is compensating the flow temperatures to a radiator system, for example – it may have reduced the flow temperature to 50 or 60C – This would not be a high enough temperature to heat the indirect hot water cylinder

For the DHW cylinder, the electric boiler heats up to a higher temperature (usually 75-80°C, to heat the DHW cylinder as quickly as possible) -the automatic control closes the heating circuit and opens the DHW heating circuit, switches on the pump and heating elements and heats to a higher temperature (75-80°C) which heats the DHW cylinder very quickly (100 litres in approx. 10 – 20 minutes! Based on a 15kW)

If you use an unvented mains cold water supply hot water storage cylinder, then you can have a powerful hot water supply delivering mains pressure showering hot water and fast filling baths.

Note – If you require a 9kW electric combi boiler or combination boiler, look at our solution – as a true 9kW electric combi won’t work correctly to produce an adequate flow rate based on the water temperatures we get in the UK and Ireland especially in the winter period – the flow rates as just pathetic and unusable – look our solution here – electric combination boilers

Open vented systems

Pressurised or open vented central heating systems? open vented systems are now old technology when it comes to a wet central heating.

You can use our boilers on an open heating system, but the require minimum head is 8 metres,

But we don’t recommend it as open vented system allow oxygen ingress into the heating water, which result in corrosion in the system, with standard radiators and some thermostatic radiator valves being manufactured in steel this is not a good idea.

Electric boiler with 9kw Output electric powered

We at Flexiheat UK limited, supply and stock a large range of electric boilers, with our 9kW electric boiler being the best on the UK and Irish markets. Having many benefits such as the best boiler modulation or turndown ratio on the market. Being extremely compact and suitable for use in a house, apartment, mobile home, or flat, along with other types of residential properties. With soft start and zero volt switching to avoid power surges.

Please don’t hesitate to contact our sales customer services team on 01202 822221 or use our email contact form via the contact tab above to message us and get the best price. We normally have stock of the electric boiler unit on the shelf, or we can arrange a delivery on a small pallet service, which can either delivered on an overnight delivery service or a 2/3-day delivery service depending on the customer requirement. All our customer invoices are inc vat, as we are vat registered company number GB236 9061 01.