Frozen pipes
Keeping water pipes above freezing in a cold snap or an outage, and what to do when one freezes.
How to keep pipes from freezing
Pipes freeze first where they are coldest: along outside walls, where the water service comes in, and in basements, crawl spaces, garages and attics (City of Toronto). Water expands as it freezes, which is what splits a pipe. The Government of Canada lists frozen pipes among the risks of a long winter outage (Get Prepared).
Prepare before the cold arrives
Find and test the main water shut-off, seal drafts, fit foam covers on exposed pipes, and disconnect the hoses and drain the outdoor taps.
Get warned early
A smart thermostat can send a low-temperature alert, but it goes quiet in a power cut, when the house starts cooling. A battery freeze sensor that sounds on its own covers that gap.
If the heat goes, drain the pipes
If an outage looks long and the house is getting cold, shut off the water main and drain the plumbing, as the Government of Canada advises.
Safety: Never thaw a pipe with a torch or any open flame, and never run a generator, barbecue, camp stove or propane heater indoors or in the garage (Health Canada). If a pipe has burst, turn off the main water supply straight away and call a plumber.
What helps
Pipe heat cable keeps the pipe that always freezes first above freezing while it has power; a freeze alert gives you time to act.
Heat cables
Raychem FrostGuard 120 V Self-Regulating Pipe Heating Cable, 6 ft
Self-regulating plug-in pipe cable for metal or plastic pipe
Frost King Automatic Electric Heat Cable Kit for pipes, 6 ft
Plug-in pipe cable that switches itself on below 38 °F
Water alarms
YoLink Water Leak Sensor 4 Starter Kit
Four app-connected leak sensors with a freeze warning
$72.99–$89.99at YoLink (YoSmart) · prices may have changedPrice checked . Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on YoLink (YoSmart) at the time of purchase will apply to the purchase of this product.Check price at YoLink (YoSmart) (opens in a new tab)
Thermostats
ecobee Smart Thermostat Enhanced
Low-temperature alerts to your phone; works without a C wire
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Our guide
Questions about frozen pipes
Does leaving a tap dripping stop pipes freezing?
It helps in a heated house during a deep cold snap: City of Toronto guidance suggests a pencil-thin stream from vulnerable taps on nights below −15 °C, with the drains kept clear. It is not a substitute for heat in a long outage: if the house is losing its heat, shut off the main and drain the system instead.
Will a smart thermostat stop my pipes freezing?
It helps if the heating still works. Google’s Safety Temperature turns the heat on even when the Nest is set to Off and notifies your phone; the ecobee sends a low-temperature alert. Neither can heat the house if the furnace or the power fails.
Will a heat cable work in a power outage?
Only if something powers it. A short pipe cable draws little, so a portable power station placed where the cable’s own cord reaches can run it indoors. A generator, which must stay outside at least 6 m from the house (Health Canada), can only feed it safely through a transfer switch or interlock fitted by an electrician.
Do I need a plumber?
Not to shut off and drain a typical house. Call a licensed plumber for a burst pipe, a pipe that stays frozen after you try to thaw it, a well or a hot-water heating system, or pipes that freeze every winter. Our frozen pipes guide covers thawing one safely.
Comes with
Cold snaps
Safe heat, pipes that stay unfrozen and an alert before the house gets cold.
Power outages
Keeping the furnace, fridge and sump pump running when the grid goes down, and connecting backup power safely.
Ice storms
Freezing rain, ice on lines, roofs and trees, and the long outages that follow.