Isolation Valve
Also known as: service valve, mini stopcock, quarter-turn valve
A small valve fitted on supply pipes to individual appliances, allowing you to isolate one fitting without turning off the mains water supply to the whole house.
Under sinks, behind toilets, behind washing machines and dishwashers — on the supply pipes.
Small brass or chrome inline valve with a flathead screw slot. Slot in line with pipe = open. Slot across pipe (90°) = closed.
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Always turn off the water supply before replacing any part. If in doubt, consult a qualified plumber. Gas components must only be worked on by a Gas Safe registered engineer. Unvented (pressurised) hot water systems must be worked on by a G3-qualified engineer. Prices shown are indicative — check retailers for current pricing.