How Long Should You Let Faucets Drip in a Freeze
Every winter, the same question resurfaces for millions of Canadians bracing for the season’s worst cold snaps: how long should you let faucets drip during a freeze? When temperatures plunge below -7°C — a threshold the GTA regularly crosses between December and March — water inside pipes can freeze and expand by 9%, generating over 2,000 PSI of pressure. Residential plumbing simply isn’t built to handle that. The result can be a burst pipe and a repair bill ranging anywhere from $5,000 to $50,000.
Winter freezing accounts for roughly 60% of burst pipe cases in Toronto, with January and February marking the peak of emergency calls. Polar vortex events can push temperatures to -25°C and beyond, turning a manageable cold night into a plumbing disaster waiting to happen. A small, steady drip from the right faucet costs almost nothing — about two cents per night — but it could be the difference between a dry home and a flooded one.
Temperature Triggers for Faucet Dripping
Below -7°C, most insulated pipes are at risk — but uninsulated pipes or those running along exterior walls can start freezing the moment temperatures dip below 0°C.
Start dripping when temperatures fall below -7°C for three or more consecutive hours, or below 0°C for four or more hours. If the power goes out during any freezing temperatures, don’t wait — start immediately. Pipes can freeze in as little as six to eight hours, which means an overnight cold snap is all it takes. Ideally, get ahead of it: begin dripping before the cold arrives, or within the first two hours of a cold event.
Once both daytime and nighttime temperatures are consistently above 0°C, it’s safe to turn off the drip.
Which Faucets to Drip and How Much
Not every faucet in your home needs to drip during a cold snap — one or two is usually enough. Focus on taps fed by pipes running along exterior walls, those in unheated spaces like garages or basements, and the faucet farthest from where water enters the house. Dripping that farthest faucet moves water through the entire plumbing system, not just a single line.
Turn on the cold tap to a slow, steady drip — roughly one drop every one to three seconds. Hot water travels through a separate pipe that’s less exposed to freezing temperatures. If both lines run through an unheated space, or if a power outage has knocked out your water heater, drip both.
On the coldest nights — think polar vortex territory — a drip alone may not cut it. When temperatures are severe, increase the flow to a thin, steady stream about the width of a pencil. Keep faucets dripping continuously throughout the entire cold period until temperatures warm again.
Winter Prep and Warning Signs
Open cabinet doors under sinks to let warm air circulate around those pipes on brutal nights. Keep your thermostat at 18°C or higher, even while you’re away; dropping it below 16°C is a gamble not worth taking.
Before the cold arrives, disconnect garden hoses and drain outdoor faucet lines. Seal gaps around dryer vents and anywhere pipes pass through exterior walls. These small steps take an afternoon and can prevent a catastrophic repair.
Know what a frozen pipe looks like:
- Little or no water from a tap
- Frost on exposed pipes
- Foul smells from drains
- Bubbling paint near an exterior wall
- Whistling or banging sounds in the walls
What to Do If Pipes Freeze
If you suspect a frozen or burst pipe, leave the faucet open and shut off the main water valve immediately. Don’t attempt to thaw pipes you can’t see or safely reach — improper thawing can cause additional damage.
Professional assessment ensures long-term winterization and prevents emergency plumbing failures. Call Drain Rescue Plumbers for immediate assistance: 1-800-568-7359.
Don’t Let a Frozen Pipe Become a Plumbing Disaster
When Toronto’s temperatures plunge and your pipes are at risk, you need a trusted expert ready to respond fast. Drain Rescue Plumbers has been proudly serving Toronto and the Greater Toronto Area since 1997, delivering reliable, experienced solutions for burst pipes, leaks, and water damage emergencies. Whether it’s the middle of the night or the coldest February on record, their team is available around the clock to protect your home. Don’t wait until a small freeze becomes a costly $50,000 nightmare — call the plumbers Toronto trusts at 1 800-568-7359, or learn more about their 24 hour plumber in Toronto.