Thaw a Frozen Pipe Without Bursting It

Category: Plumbing Emergency · Difficulty: Beginner · Time: 2.4h · Estimated cost: $40

Tools needed

Open the faucet
Open the affected faucet to its hot AND cold positions, even if no water comes out. This relieves pressure as ice melts and gives water somewhere to go.
Duration: 2 min
Locate the frozen section
Trace the line from the faucet back. Frozen sections often feel ice-cold or have visible frost. Common spots: exterior walls, attics, crawlspaces, garages.
Duration: 15 min
Apply gentle heat
Use a hair dryer on medium heat, sweeping back and forth along the pipe. Start NEAR the faucet end and work back toward the frozen section. NEVER use open flame (torch).
Duration: 30 min
Watch for water
When water starts trickling from the faucet, you're winning. Keep heat on the same area until full flow returns.
Duration: 20 min
Inspect for leaks
Once thawed, run water for 5 min and inspect every inch of that pipe with a flashlight. Cracks may show as drips or as wet spots on adjacent drywall.
Duration: 10 min
Insulate to prevent recurrence
Wrap exposed pipes with foam sleeves. For pipes that freeze repeatedly, install UL-rated heat tape per manufacturer directions.
Duration: 1h
Long-term: keep heat on, drip faucets
On any sub-freezing night, keep house above 55°F even when away, and let one faucet on each exterior wall drip.
Duration: 5 min

NEVER use a propane torch or open flame to thaw a pipe — leading cause of house fires in winter.
If you can't find the frozen section or the pipe has already burst (water spraying), shut off the main valve immediately.
Keep a towel under the area in case the pipe leaks when it thaws.

If the pipe has burst, is in an inaccessible wall, or you find multiple frozen sections in different walls, call a plumber and turn off your main.