Smart locks in a Winnipeg winter: what holds up at minus thirty

What operating temperature should a smart lock be rated for?

Most smart deadbolts come in two parts: an outside unit with the keypad or touchscreen, and an inside unit with the batteries, the motor and the electronics. Makers usually rate them separately, and the inside part is often rated for much warmer temperatures than the outside.

Here's what three makers publish for one model each:

Two things stand out:

• The outside ratings cover most Winnipeg winter nights. The lock cares about the air temperature at the door, not the wind chill on the forecast. On the rare extreme nights, a sheltered door under a porch roof, out of the wind, gives the keypad the best chance.
• The inside ratings are where people get caught. A lock rated to 0°C on the inside is fine on a door into a heated house. It's a poor choice for a door where the inside of the lock faces an unheated porch, a cold vestibule or a detached garage.

Allegion also notes that the Schlage Arrive is not intended for outdoor use such as gates or sheds, because the interior parts aren't weatherproof. That's a good rule for any smart deadbolt: use it on a door with a heated or at least sheltered inside.

These are examples, not recommendations. Ratings differ between models from the same maker, so check the spec sheet for the exact model number before you buy.

How does the cold affect smart lock batteries?

Most smart deadbolts run on AA batteries in the inside unit. Battery chemistry slows down in the cold, so a battery that's half full can behave like one that's nearly empty on a frigid morning, and the motor needs more power to drive a bolt that's stiff with cold.

What helps:

• Change batteries before winter, not when the low-battery warning finally gets your attention.
• Use the type the maker specifies. Some makers say whether alkaline or lithium AA cells are acceptable. Follow the manual.
• Watch the low-battery warning in the app or on the keypad and act on it the same week.
• Keep the door aligned so the bolt slides freely. A bolt that drags against the strike drains batteries faster in any season.

Will a keypad or touchscreen work with gloves and ice?

Physical buttons are usually easier with gloves than a touchscreen, though a thin pair of touchscreen gloves helps. Ice is the bigger issue:

• Freezing rain can glaze over a keypad. Clear it gently with your hand; don't chip at it with a key.
• Fresh snow blowing against an unsheltered door can pack into gaps. A porch roof or an overhang makes a real difference.
• Use the app or a fob if your lock supports it, so you're not punching in a code bare-handed in a blizzard.

Does your smart lock have a backup way in?

Every smart lock in Winnipeg needs a plan for the night the batteries die at minus thirty. There are two common backups:

1. A key cylinder. A regular key works the lock when the electronics don't. Keep that key somewhere you can reach from outside the house: with you, or with a trusted neighbour.
2. Emergency power on the outside. Some key-free locks have contacts or a port on the outside unit where a battery or a power bank wakes the lock long enough to enter your code.

Know which one your lock has before you need it. Our guide on what to do when a keypad lock battery is dead goes brand by brand.

The same goes for your car: if you rely on a fob, our post on a key fob not working in the cold has the backup steps for that side of a winter morning.

Does a storm door affect a smart lock?

It can. A storm door shelters the keypad from snow and freezing rain, which helps. But a storm door on a sunny side can trap heat behind the glass, and moisture can condense between the doors in a cold snap. If you have a storm door, ask the maker whether the model is suited to that setup, and keep the space between the doors dry.

What does a good smart lock installation involve?

A smart lock is only as good as the door it's on:

• Door prep: the bore holes and edge prep must match the lock.
• Alignment: the bolt must slide into the strike without dragging, or the motor strains and batteries drain.
• A full throw into a solid strike plate with long screws, exactly like a regular deadbolt. A smart lock doesn't change how the frame resists a kick. See how to secure your front door from break-ins for the strike plate details.
• Codes and users: set up user codes, delete the installer's test codes, and know how to remove a user later.

If you're choosing a lock for a Winnipeg door, we'll help you match the model to where it's going and fit it so the bolt runs freely in the cold. See smart lock installation.

The printable move-in lock checklist below includes resetting smart lock codes and removing old users, which is worth doing on day one in a new home.