Plumbers & electricians in Dulwich

Dulwich Village sits at the centre of SE21, with Dulwich Park beside it and College Road running south past the college towards Sydenham Hill. Around it are Georgian and Victorian houses, then road after road of large detached and semi detached villas, Edwardian semis and some interwar building westward towards Belair Park and West Dulwich station, with the Tulse Hill edge beyond that.

Almost all of SE21 sits within the Dulwich Estate, whose scheme of management adds a layer of consent for anything that alters the outside of a house. So the stock keeps its front and rearranges its insides. Lofts become bedrooms, box rooms become shower rooms, and the house ends up doing far more than it was plumbed for. A boiler repair in Dulwich is often a hot water pressure question, and a blocked drain in Dulwich an original run taking waste from bathrooms and shower rooms it was never sized for.

Why so many Dulwich houses run on an unvented cylinder, and what that system needs

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An unvented cylinder is a hot water cylinder fed straight off the incoming main and sealed shut. No tank in the loft, no open vent, so every hot tap and every shower runs at roughly the same pressure as the cold, which is why it suits a house with bathrooms on two or three floors. The trade off is that a sealed vessel of heated water is a controlled system, because water expands as it warms and has to be given somewhere to go. Part G treats it as notifiable work for that reason, and requires a pressure reducing valve, an expansion vessel, an expansion relief valve, a temperature and pressure relief valve on the cylinder, and a thermal cut out that will not reset itself. None of those is decoration.

The expansion vessel is the part that fails quietly. Inside is a diaphragm with a charge of air behind it, and when the cylinder heats, water pushes in and compresses that air. Over ten or fifteen years the charge leaks away or the diaphragm perishes, and on cylinders that use an internal air bubble instead, the bubble dissolves back into the water. Once expansion has nowhere to go, pressure climbs every time the cylinder reheats and the relief valve opens to let it out. What you see is water trickling from a pipe on an outside wall an hour after the heating has run. The instinct is to change the leaking valve, but that valve is the one part doing its job properly.

The discharge pipework is the part most often done badly. The short leg to the tundish is straightforward, but the pipe onwards from it has to be a size larger, has to fall the whole way with no dips, and is limited in how far it may run before going up another size again. It has to survive water close to boiling, and it has to end somewhere the water can leave safely and be seen leaving. We find them run uphill into a soil stack, buried in a boxed in void, or fitted with no tundish at all. Whether a house can take a cylinder in a given spot comes down to the main, the space and the route that pipe can honestly take.