Boiler heating element – 2.5 kW

The middle rating on this mounting, and the one most boiler blocks are built around: 2.5 kW heats water at a fair pace without asking too much of the wiring. It goes straight into the water, and the tube is stainless steel throughout, so it neither rusts nor sheds flakes into the system.

Before you order, put a calliper on the old element. This one has two Ø22 mm fittings with 120 mm between their centres, a tube of 13.8–13.9 mm and a heated section of 16.5 cm. The terminals are M5 studs. Flanges look alike from a distance, but a millimetre out on the centre distance means the nuts will not pull it home.

Scale will build on any element that sits in water; lift it out now and then and clean the tube before the deposit starts to hold the heat in.