Flow boilers are really useful for heating water and maintaining that heat in a ‘circuit’ of water where electric is the only option. Typical applications would include underfloor heating, and wet system radiators. (central heating)

But which one is right for your particular application?

The 2 things to consider would be the size needed (kW) and the right type of flow boiler for the job. To work out the correct kW rating of the flow boiler to suit the installation, you would first need to know a bit about what needs to be heated with this hot water. As an example, if the flow boiler was to provide heat for 6 average sized radiators, then you need to allow around 1.5kW per radiator. So 6x 1.5 = 9, so you would need a boiler rated at 9kw.

For a wet underfloor system, there are varying rules of thumb, but we tend to use the following:

  • 70w per m2 for timber suspended floors
  • 100w per m2 for concrete floors (in screed)
  • So, as an example, for a concrete floor 60m2 in area, you would need a 6000w (6kW) flow boiler.

Most flow boilers by the leading manufacturers can be used for both underfloor and central heating systems, with a typical temperature setting range of 35 – 75 degrees Celsius.

(Underfloor systems tend to work on the lower end of this temperature range) although the Heatrae Sadia Amptec range of flow boilers have a separate range of models for these 2 applications, with different temperature ranges for each.

Generally, these flow boilers will need the addition of a pump and an expansion vessel for installation, although there are versions done by particular brands that include these components in one neat enclosure. One of our most popular brands would be Premier Heat, by Heatrae Sadia, and we also now have the Slim Jim range from EHC.

 

We hope that helps with the selection process, but please call one of our water heating nerds on 01934 253600 for further information if required, or use the online chat, available from every page on the site: www.electricaldealsdirect.co.uk