Boiler Repair, Service & Installation in Sydenham (SE26)

The 2021 Census counted 12,976 households in SE26. 43.0% live in purpose-built flats and 17.9% in a house that has been converted or shared, so six homes in ten are flats of one kind or another. The Valuation Office’s count of the district’s properties puts 26.2% before 1900 and 15.1% between 1965 and 1972, the largest single band after the war. 76.4% of households have central heating on mains gas alone, a little above the 74.0% for England. That mix decides what a boiler call in Sydenham looks like.

Air is the simplest of those faults, and the easiest to make worse.

Air trapped in the radiators

Water in a heating circuit carries some dissolved air, and more gets in whenever the system is opened: a radiator taken off the wall to decorate behind it, a drain-down for a new valve, a new radiator added to a loft room. That air does not stay spread through the water. It collects at the highest points it can reach, which in a maisonette means the top of the upstairs radiators and any length of pipe climbing to them. The signs are easy to read. A radiator hot at the bottom and cold across the top has air in it; one warm at the top and cold at the bottom has a different problem, usually sludge, and bleeding will not shift it. Gurgling or trickling in the pipes when the pump starts is air on the move. A pump that hums but pushes little round can be holding a pocket of air of its own. In a Sydenham conversion, where a flat’s pipework may run up through two storeys of an old villa, the top floor is where it shows first, and a downstairs radiator can be hot while the bedroom above stays cold. A radiator added to a loft room later suffers most, because it sits highest of all.

Bleeding still wants doing in the right order. Heating off and the radiators cool, so the pump is not drawing air back in and nobody gets sprayed with hot water. Start on the lowest floor and finish at the top. Open each bleed valve with a radiator key only until the hiss stops and water comes, then close it. On a sealed system, every radiator bled lets out water as well as air, so the gauge on the boiler drops. Top it back up to the cold figure in the boiler’s manual before the heating goes back on.

Most combis will not light with the pressure too low.

When air keeps coming back, bleeding is treating the symptom. A system that needs bleeding every week is drawing air in somewhere or making gas inside, and either one wants finding. A gauge that falls with no water on the floor points to a leak hidden under boards or behind a bath panel. We look at the radiators, valves and pipework ourselves. If the cause sits inside the casing, an automatic air vent weeping onto the boiler’s own parts for example, that is for the engineer to open.

If the upstairs radiators have been cold at the top for years and the boiler is old as well, it may be time to weigh up the whole system, and we also arrange boiler installations for homes in SE26.