How soon can pipes freeze without heat?
Pipes in exterior walls, crawlspaces, garages and attics can freeze within hours once the heat fails on a below-freezing night, even while the middle of the house still feels livable.
Water expands as it freezes, and the pressure buildup between the ice and a closed faucet is what bursts pipes. Keeping water moving and warm air reaching pipes buys time.
Where pipes freeze first
- Kitchen and bathroom sinks on exterior walls
- Pipes in unheated crawlspaces and basements
- Garage water lines and laundry hookups
- Outdoor hose bibs and irrigation lines
- Attic pipes and pipes under bonus rooms
- Pipes near foundation vents or rim joists
Protect pipes while heat is out
- Open cabinet doors under sinks on outside walls.
- Let cold and hot taps drip at those sinks.
- Close garage doors and crawlspace vents.
- Keep interior doors open so any remaining warmth spreads.
- Know where your main water shutoff is, and test that it turns.
- Call for emergency HVAC service so heat is restored before pipes freeze.
HVAC or plumber?
| What you see | Who to call |
|---|---|
| Heat out, pipes not yet frozen | Emergency HVAC: restoring heat protects the pipes |
| No water at one faucet, heat working | Plumber: a frozen section needs thawing |
| Water spraying or ceiling leaking | Shut off the main water, then call a plumber |
| Boiler pressure dropping after a freeze | HVAC: possible frozen or burst hydronic pipe |
Thawing pipes safely
Use a hair dryer, heating pad or space heater, never an open flame or torch. Keep the faucet open while thawing so melting water can escape. If you can't reach the frozen section, call a plumber.
Hydronic and boiler systems
Homes with boilers have water-filled heating pipes too. If baseboard loops run along exterior walls or through crawlspaces and the boiler stops, those loops can freeze and split.
If the boiler is out in severe cold, mention it right away; it changes how urgent the call is.
Frozen pipe FAQs
What temperature should I keep the house at to avoid frozen pipes?
Many plumbers recommend at least 55°F, including when you travel. Homes with pipes in exterior walls may need more in extreme cold.
Does homeowners insurance cover burst pipes?
Many policies cover sudden bursts, but may exclude damage if the home wasn't kept heated. Check your policy.
Next steps
Ready to get it fixed? Call (888) 555-0143 to reach a licensed provider in your area. Related guides:
Busy winter markets: emergency HVAC repair in Texas · emergency HVAC repair in North Dakota · emergency HVAC repair in Minnesota · emergency HVAC repair in New York · emergency HVAC repair in Massachusetts · emergency HVAC repair in Tennessee · all states.