Moisture is the real problem
Snow melts into the keyway during the day and freezes at night. Ice and grit build up around the pins, and a key that turned easily in October starts to drag by January.
What not to do
Forcing the key or pouring hot water on the lock makes things worse. The key can snap inside the cylinder, and the water refreezes deeper inside. A lock that needs force is a lock that needs service.
Simple prevention
Have stiff exterior locks cleaned and lubricated with a dry lubricant before the cold sets in, and make sure the door is not sagging onto the strike. If a lock is already sticking, call for a free quote by phone before it becomes a lockout.
Related service
Lock Repair →
Keys that stick, handles that sag and latches that miss the strike, put right.