Frozen Pipes: How to Thaw Them Safely (and When It’s Already Too Late)
Open the affected faucet first, locate the frozen section (usually an exterior wall, crawl space, or unheated area), and thaw it gradually with a hair dryer, heat lamp, or heating pad — never an open flame. Keep the faucet open: flowing water speeds melting and relieves the pressure that bursts pipes. If you see a bulge, crack, or any water seeping, stop — shut the main valve and jump to the burst pipe playbook.
How Do You Thaw a Frozen Pipe, Step by Step?
- Open the faucet the pipe feeds — both hot and cold handles. This relieves pressure and lets meltwater flow.
- Find the freeze: follow the line from the dead faucet toward the meter; frozen sections are often frosty, bulged, or simply the coldest stretch in an exterior wall, crawl space, attic, or garage.
- Apply gentle heat from the faucet side toward the blockage: hair dryer, heat lamp, space heater in the room, electric heating pad wrapped on the pipe, or towels soaked in hot water.
- Never use a propane torch, open flame, or anything that chars — you’ll boil steam inside the pipe (explosive), ignite framing, or melt PEX.
- Keep heat moving 30–60 minutes; full flow back at the faucet means you’re done. No luck, or the pipe is inaccessible inside a wall — that’s a plumber call before it bursts.
When Is It an Emergency?
| Situation | What it means | Move |
|---|---|---|
| One faucet dead, no visible damage | Localized freeze | DIY thaw above |
| Multiple faucets dead | Freeze near the main / meter | Thaw what you can reach; call a plumber |
| Bulging or cracked pipe | Burst waiting for thaw | Shut the main now — water shows up when it melts |
| Water already appearing | It burst | Burst pipe playbook — main valve, power, document |
| Pipe inside a finished wall | No safe DIY access | Plumber with thermal tools ($150 – $500 typical call; after-hours +50–100%) |
How Do You Keep Pipes from Freezing Tonight?
During the cold snap (tonight’s checklist):
- Drip both hot and cold faucets on exterior walls — moving water resists freezing
- Open cabinet doors under sinks on exterior walls so room heat reaches the pipes
- Keep the thermostat at one temperature day and night, never below 55°F — including when traveling (most policies expect “reasonable heat” for freeze coverage)
- Close garage doors; disconnect garden hoses (a connected hose freezes the sillcock back into the wall)
Before next winter: insulate pipes in unheated spaces (foam sleeves are $1–2/ft DIY), seal rim-joist drafts, add frost-proof sillcocks, and in brutal climates ask about heat cable. Cold-climate homeowners in Minneapolis, Chicago, and Boston treat this as annual routine — see local rates in those guides.
Frequently Asked Questions
How do I know if my pipes are frozen and not something else? Deep freeze outside + one or more faucets producing a trickle or nothing = freeze until proven otherwise. A single dead faucet with normal weather points to the fixture instead.
How long does it take pipes to thaw? With active heating (hair dryer/heat lamp), commonly 30–60 minutes per section. “Wait for the weather” thawing works too — but that’s when bursts reveal themselves, so shut the main if you leave or see damage.
Will frozen pipes always burst? No — water expands ~9% when freezing, and whether the pipe survives depends on material and how trapped the pressure is. That’s why opening the faucet (pressure relief) is step one.
Does insurance cover frozen pipe damage? Burst-from-freeze damage is generally covered if you maintained reasonable heat. Leave the house unheated in January and the claim gets hard. Keep thermostat records/photos if you travel in winter.
What temperature should I keep my house to prevent frozen pipes? 55°F minimum, day and night, occupied or not. The cost of that heat is trivial against a $400–$2,000 burst repair plus water damage.
Last updated: June 10, 2026. Sources: American Red Cross frozen pipe guidance; Insurance Information Institute winter claims data; plumber rate ranges cross-checked with BLS wage statistics. Never use open flame on pipes.