Water heating element – clip, power – 2.0 kW

Short enough for shallow tanks: the working zone is just 18.5 cm from the fitting skirt, within 5% either way. Where a larger clip would touch the far wall, this size fits.

Two kilowatts give unhurried heating without much strain on the wiring. The 10 mm stainless tube is folded twice; at the ends sit two fittings of 14 or 16 mm diameter with 60 mm between centres, the same spacing as the rest of the clip family, so the mounting holes stay as they are.

Run it under water only, and knock the scale off once a year; the tube will last.