Boiler Repair, Service & Installation in Herne Hill (SE24)

The 2021 Census counted 7,285 households in SE24, and 78.8% heat with mains gas alone. 29.1% live in terraced houses and 27.2% in houses that have been converted or shared, and the Valuation Office puts 52.5% of the district’s properties before 1900, with another 12.1% from 1900 to 1918. Houses of that age were built with solid brick walls rather than two skins with a cavity between, and the radiators in them were fitted long after the bricks went up, often sized by eye or carried over from the room’s last heating.

Some rooms need more radiator, not more boiler.

Radiator size against a cold room

Every room loses heat through its walls, windows, floor and ceiling, and through draughts, and a radiator has to put back at least as much as the room loses on a cold day. A solid brick wall lets more heat through than a cavity wall, so a front room in a Herne Hill terrace, with a bay of old glazing, a high ceiling and perhaps a suspended timber floor, needs a good deal more radiator than a room of the same floor area in a newer house. When the radiator is hot all over and the room still will not reach temperature on a cold evening, the radiator is too small for the room. A bigger boiler will not fix that, because the boiler can only heat the room through the radiator. The answer is more surface: a bigger radiator, a double panel in place of a single, a second radiator on another wall, or a radiator moved under the window so it warms the cold air falling off the glass. Draught-proofing an old sash window helps whichever of those you choose.

Sizing a radiator starts with a room-by-room heat loss figure: the size of each wall, window and floor, what each is made of, and how warm the room should be. We work it out for the rooms you are unhappy with, then choose radiators by their stated output, which makers publish for every size. Where the pipework allows, a larger radiator can usually go in the same place on new tails, and a double panel takes little more wall.

Balancing comes first if the radiator is not hot all over.

Fitting a new radiator is plumbing we do ourselves: drain, fit, refill, bleed and look at the pressure before we go.

If the whole house is short of heat and the boiler is old, the radiators and the boiler are worth sizing together, and we also arrange boiler installations in SE24 on that basis.