Why locks freeze
- Moisture gets into cylinders and freezes.
- Cold makes metal contract and lubricants thick.
Safe steps
- Use a de-icer made for locks, sparingly.
- Warm the key with your hands, not a flame.
- Do not pour hot water over a lock or door.
Doors that swell or shrink
- Loose hinge screws are the usual cause of a door that will not latch in winter.
- Tighten the top hinge first.
Car doors
- Do not pull hard on a frozen handle.
- Try another door.
When to call
If the key will not turn, stop. Forcing it can snap the key.
Prevention in autumn
Apply a dry graphite or lock-specific lubricant to exterior cylinders and padlocks before the first freeze. Check the weather stripping so meltwater does not run into the keyway. Keep a spare key in a warm place inside the house or with someone you trust.
If a lock has already frozen
Do not force the key. Warm it in your hand and try gently, or use a commercial lock de-icer. Do not pour hot water over the lock; it refreezes and can crack plastic parts. If the lock still will not turn, call a technician instead of dismantling it in the cold.
Doors that shrink and swell
In Scarborough, temperature and humidity swings can make a door bind against its frame. A latch that lines up in summer may miss the strike in January. If the problem returns each winter, the strike may need adjusting or the hinges tightening, which is cheaper than a lockout.
Need a locksmith? See our emergency locksmith and pricing and process pages.