Boiler Repair, Service & Installation in Catford (SE6)

The 2021 Census counted 21,993 households in SE6. Just over half live in a terraced or semi-detached house, 30.6% and 19.6%. The Valuation Office’s count of the district’s properties puts 43.8% between 1900 and 1939, with a further 29.9% older than that, and 74.4% of households heat with mains gas alone. A boiler call in Catford is mostly a call to a house of that age, with its radiators added and moved over the decades by different hands.

A cold back bedroom is a flow problem.

Balancing radiators in a long house

Hot water leaves the boiler and takes the easiest way round the house. In a terrace with a back addition, the radiators in the front room and hall are a short run from the boiler, and the bedroom over the kitchen at the back can be the far end of a long one. Left alone, the near radiators pass most of the flow and the far one gets what is left, so it warms slowly or barely at all, and the room thermostat in the warm hall can switch the heating off before the back of the house has caught up. Each radiator has a valve at each end. One is the valve you turn, by hand or with a thermostatic head. The other, under a plain plastic cap, is the lockshield, and it is set once with a spanner or key to decide how much water that radiator is allowed to take. Balancing means closing the lockshields down on the radiators that get hot first and opening them on the ones that lag, until the house warms together. It is slow, careful work with the heating running, a thermometer on the pipes and several rounds of small turns.

Balance is easily lost. A new radiator, a radiator moved for a kitchen refit, a valve replaced, a system drained and refilled, or a new boiler with a different pump can all change how the water divides. If one room has been cold since a particular job, that job is the first clue.

We balance systems ourselves; it is plumbing, not gas work.

Before balancing, we make sure the slow radiator is not cold for another reason: air at the top, sludge along the bottom, or a valve stuck shut. Each of those has its own fix, and balancing a radiator that is blocked only moves the problem round the house.

If balancing shows that the boiler cannot keep up with the house at all, the next conversation is sizing, and we also arrange boiler installations in SE6 with every radiator taken into account.