Ensuring that a new boiler can cope with the heating and hot water demands of a home is an essential requirement. Quite naturally, a five-bedroom detached house will need a larger boiler than a two-bed terraced house.
Boiler size
Domestic boiler size, or output, is measured in terms of the heat output, in Kilowatts, which is commonly shortened to kW. Domestic boiler sizes (output) typically range from 5 to 35 kW.
Hot water demand
One of the key considerations when deciding on the size of your boiler is how much hot water will be used on a daily basis. Consider how many showers, baths and appliances use hot water, and how often they are used.
Size of property
As well as providing your hot water, the boiler will probably be the main source of heating for your property. This means that it is essential to choose a boiler that is large enough to provide sufficient heat output to supply your entire property.
Radiators and bathrooms
Typically, hot water radiators can consume 1.5kW and a hot water cylinder 3kW. It is therefore relatively straightforward to count the number of radiators in your property, and then multiply by 1.5 to get a rough indication of the boiler output required to supply the radiators (and adding 3kW for the water tank).
For many households with a single bath and shower, a 24-27 kW boiler is generally recommended. If there is an additional en-suite bathroom, it may be advisable to choose a larger 30-35 kW boiler.
Underpowered
An underpowered (undersized) boiler will struggle to meet the heating demands of your home, resulting in a shortfall of heating to your radiators, or insufficient hot water to your taps, shower/bath, and appliances.
Overpowered
An overpowered (oversized) boiler will not provide any additional benefits and although modern boilers will modulate their output to meet the lower demands. Spending more money on a boiler model that is not needed is unnecessary and is likely to result in a higher energy bill and wasted gas.
Qualified advice
Charles Clarke can provide an unbiased, professional assessment, advice, and recommendation in regard to the size and type of boiler most suitable for your property, hot water and heating needs.
