Frozen Pipes in Minnesota: Prevention, Detection, and Emergency Thawing

Pipes can freeze in exterior walls, unheated spaces, or cold drafts even when the rest of the house is heated. Protect exposed lines before freezing weather, disconnect outdoor hoses, and know where the main shutoff is. If a pipe freezes or bursts, avoid electrical hazards and shut off the water only if you can reach the valve safely.

By Steve Grohn. Published January 15, 2026. Updated November 12, 2026.

Why pipes freeze in a heated home

A pipe in an exterior wall, attic, crawl space, garage, or draft may be colder than the room thermostat. Freezing depends on the pipe and water temperature, exposure time, insulation, and available heat. The National Weather Service explains that wind can speed cooling toward the actual air temperature, but wind chill cannot cool a pipe below that temperature. There is no single safe outdoor temperature for every installation.

Protect pipes before freezing weather

• Insulate accessible exposed pipes and seal cold drafts. Insulation slows heat loss but does not supply heat.
• Disconnect garden hoses, including from frost-free faucets. A correctly installed frost-free faucet reduces risk when its valve remains in heated space and the faucet can drain, but it is not freezeproof.
• Maintain heat while away and arrange for someone to check the home. An indoor thermostat setting alone cannot guarantee warmth at every pipe.
• Locate the main water shutoff. Do not force a stuck, corroded, or leaking valve. Arrange service before an emergency.

The EPA’s winter weather guidance covers preparing pipes and the home for cold weather. For the outdoor fixture details, use our faucet and hose-bib winterizing guide.

Signs of a possible freeze

A faucet that slows to a trickle or stops while other fixtures work, or frost on an exposed pipe, can signal a frozen line. A blockage or other problem can also cause reduced flow. Call a plumber if the cause is unclear.

If a pipe may be frozen

1. Check the area for electrical hazards first. Never enter standing water or handle wet electrical equipment. If safe isolation is not possible, stay away and call the utility or emergency services for help.
2. If you can safely reach the main shutoff, close it to limit water damage if the pipe splits. Open the affected faucet to relieve pressure.
3. For an accessible pipe, apply warm towels from a dry, safe location. Never use a torch or open flame. If using an electrical appliance or heat cable, follow its instructions and keep it and its connections dry. Do not leave a space heater unattended.
4. If the pipe is concealed, inaccessible, damaged, or you cannot safely thaw it, call a plumber promptly. Do not open walls around suspect asbestos insulation.

If a pipe bursts

Stay clear of standing water and wet electrical equipment. Close the main water valve only if it is safe to reach. Do not enter water to access a breaker or operate electrical appliances. If electricity cannot be isolated safely, stay away and call the utility or emergency services. Once safe, open a faucet to relieve pressure and photograph damage for your insurer.

If the water supply is isolated or the water heater could drain, consult its manufacturer instructions and a plumber about shutdown. Do not operate controls in a wet or unsafe area. Do not use fans or other electrical equipment in wet conditions. The CDC explains electrical safety around standing water.

Call 651-738-0580 for help. Phones are answered 24 hours a day. Emergency service is available outside office hours; call to confirm response timing. Our emergency plumber page explains the next steps.