Vehicles are not much use if you can’t get inside them. When door locks freeze, it may seem like a mundane problem. However, it can be quite a challenge to solve, especially if you don’t have any proprietary door lock de-icer and the locks are very iced up. In this case, a little improvisation is called for.
You should never pour hot water onto or into a frozen lock. This could actually make the problem worse, as hot water freezes faster. Instead, pour the hot water into a plastic bottle, replace the cap and press the side of the bottle against the lock. The heat should transfer into the lock barrel and melt the ice.
Boil the kettle and pour some boiling water into a mug. Dip the end of your car key into boiling water for a few seconds. Shake off any water so the key is dry, then insert it into the lock as far as it will go. Don’t force the key in, just dip the end in the water again and repeat the process, as necessary. Sooner or later, even the most frozen lock should allow the hot key to enter.
Use a penetrating oil spray to de-ice your car locks in an emergency. Insert a straw into the spray nozzle orifice for enhanced spray direction facilitation. Alternatively, use a penetrating oil spray whose can has a flip-up hinged straw attached to an arm. A penetrating oil spray will not only defreeze your locks, but will also lubricate the mechanisms and help prevent refreezing.
Heat up a wheat bag, or similar, in a microwave oven and hold it against the lock to enable heat transference. Alternatively, point the nozzle of a hairdryer at the lock, if feasible and safe. You can also squirt a little hand sanitizer into the lock to achieve the desired result.