Retrofits are fuelspecific so see the following

Retrofits are fuel-specific, so see the following sections for retrofit information. Generally speaking if you opt for a combi and you live in an apartment or a terraced house with up to 10 average size radiators and 1 bathroom, you will require a boiler with an output of between 24-27kw a medium to large 3-4 bed house will require a combi boiler with a higher output.

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