Boiler kW calculator
Answer five quick questions and see the combi size band we would fit in your home, and whether a system boiler would suit you better. Same rules as our instant quote.
How many bedrooms?
How many bath tubs?
How many separate showers?
Count showers in their own cubicle, not one over the bath.
What kW means for a combi
On a combi boiler the kW figure is really about hot water. It is how much heat the boiler can put into the water passing through it while a tap or shower is running, so a bigger number means a stronger, steadier flow. A 24 kW combi runs one shower well. 30 to 32 kW copes with a bath plus a separate shower, or two bathrooms, without the second one turning lukewarm. 36 kW is for large homes. Heating the radiators needs far less than any of these, which is why bedrooms and bathrooms, not floor area, drive the size.
When a system boiler is the better answer
A combi heats water as you use it, so it can only serve so many outlets at once. A system boiler heats a cylinder instead, and a full cylinder will run two showers together without either one dropping. We would point you towards a system boiler when your home has five or more bedrooms, when two bathrooms are in use at the same time most mornings, or when you already have a cylinder and a like-for-like swap is the simplest job. If you have a system or standard boiler now and want a combi, that is possible too. The cylinder comes out and the pipework changes, and the quote prices that as its own line.
How we size it
- Bedrooms set the heating size. More rooms, more radiators.
- Two baths, two separate showers, or a bath plus a separate shower means high hot water demand, and we only offer boilers rated for it.
- Property type and your current boiler are carried into your quote, so you only answer once.
- The result is indicative. The free survey checks radiators, mains water flow and the flue before we confirm the size and lock in your price.
Rather talk it through? Call 07969 110679 and ask for Richard.
