How to Prevent Frozen Pipes (and Thaw Them Safely)
A plain checklist for before and during a freeze, plus what to do when only a trickle comes out.
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Water expands as it freezes, and that pressure can split metal or plastic pipes. A few steps before and during a cold snap can save a costly repair.
Pipes that freeze most often
- Pipes exposed to severe cold, such as outdoor hose bibs, pool supply lines and sprinkler lines.
- Supply pipes in unheated spaces: basements, crawl spaces, attics, garages and kitchen cabinets.
- Pipes along exterior walls with little or no insulation.
Before the cold arrives
- Drain pool and sprinkler supply lines per the installer’s directions. Do not add antifreeze unless told to.
- Remove, drain and store outdoor hoses. Close the inside valve to each hose bib and leave the outside bib open so leftover water can expand.
- Add insulation to attics, basements and crawl spaces.
- Insulate exposed hot and cold pipes with pipe sleeves or UL-listed heat tape or heat cable.
During a freeze
- Keep garage doors closed if supply lines run through the garage.
- Open kitchen and bathroom cabinet doors so warm air reaches the plumbing. Move cleaners out of children’s reach.
- Let cold water drip from faucets served by exposed pipes.
- Keep the thermostat at the same setting day and night.
- If you travel, leave the heat on at 55 degrees F or higher.
If a pipe freezes
- Suspect a freeze if only a trickle comes out of a faucet.
- Keep that faucet open so water can flow as the ice melts.
- Warm the pipe with an electric heating pad, a hair dryer, a space heater kept clear of flammables, or towels soaked in hot water. Never use an open flame.
- Keep heating until full pressure returns, then check every other faucet.
A space heater can help warm a cold cabinet or room. See our space heater comparison for safety specs.
Next steps
At a glance
| When | Red Cross step |
|---|---|
| Before cold | Drain hoses, pool and sprinkler lines; insulate attics, basements and crawl spaces |
| Before cold | Sleeve exposed pipes or add UL-listed heat tape or cable |
| During a freeze | Open sink cabinets, drip cold water, keep the thermostat steady |
| Away from home | Keep heat at 55°F or higher |
| Frozen pipe | Keep the faucet open and warm the pipe; never use an open flame |
Related: 3M vs Frost King window kits and how to weatherstrip.
Frequently asked questions
What temperature should I leave the heat at when away?
The Red Cross says to leave the heat on and set it no lower than 55 degrees F.
Does dripping a faucet help?
Yes. The Red Cross says running water through the pipe, even at a trickle, helps prevent freezing. Drip cold water from faucets served by exposed pipes.
Can I use a torch to thaw a pipe?
No. The Red Cross says not to use a blowtorch, kerosene or propane heater, charcoal stove or any open flame. Use a heating pad, hair dryer, space heater kept away from flammables, or hot towels.
