Winter Lock Problems and How to Prevent Them

Locks don't get much sympathy in winter, but cold weather genuinely does cause its own set of problems worth knowing about.

Frozen locks

Moisture that gets into a cylinder can freeze overnight, jamming the mechanism completely. Warming the key gently, rather than forcing it, is usually the safest first step.

UPVC doors dropping in the cold

Temperature changes can cause UPVC frames to contract slightly, which sometimes throws the multipoint hooks out of alignment with the keeps — the same fix as door sag in other seasons, usually a hinge adjustment.

Car locks and winter

Vehicle door locks and boot locks can freeze the same way house locks do, especially after a wash or in damp weather followed by a hard frost.

Prevention

A light coating of dry lubricant before winter sets in helps keep moisture from settling in the mechanism and freezing later.

If a lock is already frozen

Avoid pouring hot water directly onto a metal lock, which can crack cold metal or refreeze instantly. A gently warmed key, or a proper de-icer spray, is a safer approach.