What to do if?Reviewed: 2025-12-27~1 min

What to do if pipes freeze overnight during a severe winter power outage

Short answer

⚠️Depends / use caution

It depends on whether the pipe has burst, where it’s located, and if you can safely warm it without electricity.

Why people ask this

Overnight outages during severe cold mean you can’t use electric heat or hair dryers to thaw pipes. The risk also changes at sunrise when temperatures and power may return, causing sudden thawing and leaks. People want to know what’s safe to try in the dark without power, how to prevent a burst when pressure builds, and how to prepare for the moment electricity comes back.

When it might be safe

Turn off the home’s main water supply and open cold and hot faucets slightly to relieve pressure until power returns
Gently warm accessible frozen sections using non-electric methods like warm (not boiling) towels or hot-water bottles refreshed from a gas stove or camp kettle used outdoors
Open cabinet doors and interior doors to let any available indoor warmth reach pipes, especially on exterior walls
Add dry towels/blankets and foam or newspaper wrap around exposed pipes to slow further freezing overnight
If you have a properly vented generator outdoors, power a small space heater in the affected room via a heavy-duty cord through a window, keeping combustibles clear

When it is not safe

Using open flames (torches, candles, gas stoves as room heaters) or unvented fuel appliances indoors during the outage
Pouring boiling water directly on pipes or fittings, which can crack them and cause scalds in a dark, cold space
Running a vehicle or generator in a garage to warm the house, even with the door open—carbon monoxide can accumulate
Beating, prying, or trying to chip ice from pipes or meters, which can rupture lines
Cranking electric heat tapes or space heaters unattended the moment power returns without inspecting for leaks

Possible risks

Hidden bursts that only reveal themselves when power returns and the line thaws, causing sudden water damage
Pressure buildup in a sealed line overnight that can split pipes or fittings
Carbon monoxide poisoning from improper indoor heating during the outage
Slip, fall, and scald hazards when working in the dark with hot water or makeshift thawing
Electrical shock or appliance damage if wet areas are energized when service is restored

Safer alternatives

If you suspect a burst or can’t locate the freeze, shut off the main and wait for daylight or power restoration, then call an emergency plumber
Use a neighbor’s powered outlet or a community warming center to run a small heater briefly in the affected room while you monitor the pipe
If temperatures will stay below freezing for days, drain the system: shut the main, open lowest and highest faucets, and flush toilets to reduce remaining water
Stage towels, buckets, and a flashlight by suspect areas before power returns so you can spot and contain leaks immediately
After thawing, insulate exposed runs, seal drafts near sill plates, and let vulnerable fixtures drip during future outages to keep water moving

Bottom line

Overnight in a severe outage, focus on pressure relief, gentle non-electric warming, and safety. Shut off water if you suspect a burst, avoid flames and unvented heaters, and be ready for leaks when power and thawing return.