How to prevent frozen pipes
The forecast says single digits tonight and you are leaving for the weekend. To keep pipes from freezing, set the heat to about 55 degrees or higher, open the cabinets under sinks on outside walls, let the coldest faucet run a pencil thin stream, and unhook any garden hose. If a tap gives only a dribble, close the main water valve before the pipe thaws.
Why it matters: A single frozen pipe can split and flood a home the moment it thaws.
Steps
- Before winter, find the main water valve and check that it turns.
- Unhook garden hoses and, if your home has one, close the indoor valve to each outside faucet and open the faucet to drain it.
- On very cold nights, set the thermostat to about 55 degrees or higher, even if you are away.
- Open cabinet doors under sinks on outside walls so room heat reaches the pipes.
- Let the faucet farthest from the main valve run a pencil thin stream of cold water overnight.
- If a tap gives only a dribble, close the main valve, leave that tap open and call a plumber or your landlord.
- Warm a frozen pipe only with a hair dryer or warm towels while you watch it, never a flame or a space heater left alone.
Stop and call a professional if
- a pipe has burst or water is leaking near outlets, the panel or light fixtures: close the main valve, stay away from the wet area and call a plumber or your landlord
- you cannot find or turn the main valve: call a plumber, or your landlord if you rent
Questions to ask the professional
- Which pipes in this home are most likely to freeze?
- Should any pipes here be insulated or rerouted?
Common mistakes
- Turning the heat off completely while traveling in winter.
- Leaving a hose attached to an outside faucet.
- Thawing a pipe with a torch or open flame.
Teach this to someone
A one page sheet for showing a friend, a teenager or a parent: what to say, what to show, and one question to check it landed.
Teach: How to prevent frozen pipes
What to say
The forecast says single digits tonight and you are leaving for the weekend. To keep pipes from freezing, set the heat to about 55 degrees or higher, open the cabinets under sinks on outside walls, let the coldest faucet run a pencil thin stream, and unhook any garden hose. If a tap gives only a dribble, close the main water valve before the pipe thaws.
What to show
- Before winter, find the main water valve and check that it turns.
- Unhook garden hoses and, if your home has one, close the indoor valve to each outside faucet and open the faucet to drain it.
- On very cold nights, set the thermostat to about 55 degrees or higher, even if you are away.
- Open cabinet doors under sinks on outside walls so room heat reaches the pipes.
- Let the faucet farthest from the main valve run a pencil thin stream of cold water overnight.
- If a tap gives only a dribble, close the main valve, leave that tap open and call a plumber or your landlord.
- Warm a frozen pipe only with a hair dryer or warm towels while you watch it, never a flame or a space heater left alone.
Where it stops
Stop and call a professional if a pipe has burst or water is leaking near outlets, the panel or light fixtures: close the main valve, stay away from the wet area and call a plumber or your landlord.
Check question
A kitchen tap gives only a dribble on a frozen morning. What first?
Answer: Close the main water valve. Closing the main valve limits the flood if the pipe has split.
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Quick quiz
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Related skills
Sources
- US home winter weather preparedness guidance, 2025. Reviewed September 28, 2026.
Written in our own words from the sources above. It is general information, not advice for your situation; where a professional, your doctor or your lease says something different, follow them.
Last reviewed . First published .