Combi Boiler 24KW To 27KW
Small House or Flat Combination Boilers. Combi boilers are available in three size ranges 24 to 27kw, 28 to 34kw and 35 to 42kw.
As a rough estimate most flats, apartments and smaller houses, with up to 10, average size radiators will require a 24 to 27kw Combi Boiler. (This Category)
For a medium to large 3-4 bed house with up to 15 average size radiators a 28-34kw Combi Boiler would be installed.
A 35kw and a 42kw Combi boiler would be for a large house with anything up to 20 average size radiators.
For properties where a higher demand of hot water is needed the higher the kw of the boiler the better, however combi boilers do not cope well with 2 showers running at the same time in the same property.only Vaillant 937 design to run 2 shower at same time.
Where this is a requirement a system boiler with an unvented cylinder should be considered.
This information is not going to be accurate for every property as room sizes can vary wildly from property to property, but will give you a good idea when consulting with a heating engineer over your needs..