Frozen car lock or door in Winnipeg: what to do (and why not hot water)

Should I try the other doors and the trunk first?

Yes, every time. Ice doesn't form evenly. The driver's door takes the wind and the slush from the street, while the passenger side or the hatch is often fine. AAA's first piece of advice for a frozen lock is exactly this: if the lock is frozen and the fob isn't helping, try the locks on your other doors (AAA via 6abc).

Once you're in through any door, start the car, let the heater work on the cabin, and the frozen door will often free itself from the inside within a few minutes.

Does lock de-icer work, and why not hot water?

Lock de-icer works. It is made to melt ice inside the cylinder and it evaporates rather than refreezing. Squirt it into the keyhole, wait a moment, then try the key gently.

Hot water is the classic mistake. AAA is blunt about it: never pour hot or boiling water on your car, because it can shatter the glass. Even when the glass survives, the water runs into the lock, the latch and the seals, and in our cold it refreezes within minutes, usually deeper than the original ice.

The catch with de-icer is where you keep it. CAA's winter kit advice is to keep lock de-icer with you, not in the vehicle, in extreme cold (CAA emergency kit). A can in the glovebox is no help when you can't open the door.

No de-icer? What else can I use on a frozen car lock?

Hand sanitizer is the best stopgap most people have in a coat pocket. AAA suggests a little hand sanitizer or isopropyl alcohol on the key so it can slide in, then turning it gently. The alcohol lowers the freezing point of the ice it touches.

You can also warm the key itself:

• Hold the metal blade in your gloved hand for a minute, or breathe on it through cupped hands.
• If you warm it any other way, keep the plastic head away from heat. Many keys have a transponder chip or a fob in that head, and melting it creates a second problem.
• Never use a lighter or any flame anywhere near a can of de-icer. Most de-icers contain alcohol and are flammable.

Insert the warmed key, wait a few seconds, and turn with light pressure. Repeat rather than forcing.

The lock turns but the door won't open. Now what?

That's the seal or the latch, not the lock. Water has frozen the rubber gasket to the door frame, and pulling hard on the handle can tear the seal or snap the handle.

Try this instead:

1. Push firmly inward on the door, all around the edge, to crack the ice bond.
2. Pull the handle and hold it out while you push and pull the door gently.
3. Get in another door, start the car and let the heat soften the seal from inside.

If the handle itself feels stiff or springy and won't come back, leave it. A broken interior latch rod is much more work than waiting ten minutes for the cabin to warm up.

Why shouldn't I force a frozen key?

Because a frozen lock is a nuisance, and a key snapped off inside the cylinder is a repair. Brass keys are soft, and a cold key in a frozen cylinder is more likely to twist and break than you'd think. Once half the key is inside the lock, de-icer won't help, and the car now needs the broken piece extracted and possibly a new key cut.

A bent key is a warning sign. If the key has started to twist, stop and switch to de-icer or a call.

How do I stop my car doors freezing shut in a Winnipeg winter?

A few habits remove most frozen mornings:

If you rely on the fob, it helps to know what to do when the fob itself gives up in the cold. That has its own guide: key fob not working in cold weather.

A note on remote starters: they are a gift in January, but never leave the only key in a running car, and never remote-start a car parked in a closed garage. Health Canada advises against idling a vehicle in the garage even with the door open, because carbon monoxide builds up and can seep into the house (Health Canada). If a child or pet is locked in a car, call 911 first.

When should I call a locksmith for a frozen car lock?

Call when you've tried the other doors, the de-icer and a warmed key, and you're about to reach for force. That's the moment a frozen lock becomes a broken one. Call too if:

• the key has bent or snapped in the lock,
• the key is locked inside the car,
• a door has been forced and now won't latch or lock.

A locksmith has tools made to open a car door without prying at it, and can deal with a broken key or a lock that has stopped working. If you're locked out right now, see car lockout help.

If it's the garage door that froze shut instead of the car, the causes and fixes are different: see garage door won't open in cold weather. And if you've lost the key altogether, read can a locksmith make a car key without the original.