Plumbing guide
Frozen pipes: how to thaw them safely and what to do if one bursts
By the Home Doctor team · Reviewed
Quick answer
No water or only a trickle from a faucet in freezing weather usually means a pipe has frozen, most often under a sink or in a wall on an outside wall, or in a crawl space, garage or attic. Find your main shut-off first, then open the faucet and warm the pipe with a hair dryer, heating pad or warm towels, starting nearest the faucet. Never use an open flame, torch or propane heater. If a pipe has split, shut off the main and call a plumber: a burst pipe repair typically runs $200 to $1,000, plus drywall and cleanup if it's in a wall.
- How urgent
- Urgent
A frozen pipe can split and flood the house as it thaws, so deal with it today. Leaving the faucet closed lets pressure build behind the ice. It becomes 'stop and call a pro now' once a pipe has burst or water is near wiring.
- DIY or pro
- DIY if handy
Thawing a pipe you can reach with gentle heat is DIY. A frozen section you can't find or reach, and any split or burst pipe, are for a plumber.
Stop and call a pro now if
- A pipe has burst, or water is spraying or pouring: shut off the main water valve, turn off the water heater (its breaker, or the gas control to Pilot or Off), and call a plumber.
- Water is near outlets, fixtures, appliances or the electrical panel: switch off the breaker for that area from a dry spot. If you'd have to stand in water to reach the panel, stay out and call an electrician or your utility.
- A ceiling is sagging or bulging with water: keep everyone out from under it. It can come down suddenly.
- Never thaw a pipe with a torch, open flame, or propane or kerosene heater: they can start a fire inside the wall, and fuel-burning heaters indoors can fill the house with carbon monoxide.
Common causes and how to tell them apart
1. Pipes under a sink on an outside wall
- How to tell
- One kitchen or bathroom sink against an exterior wall has no water or a trickle. The pipes in the cabinet feel ice cold or have frost on them.
- What fixes it
- Open the cabinet doors and warm the pipes with a hair dryer or heating pad, starting at the faucet end. Later, seal gaps where the pipes come through the wall and insulate them.
2. Pipe inside an exterior wall
- How to tell
- A fixture on an outside wall is dry, but the pipes you can see under it aren't frozen. Often a bathroom or laundry on the cold, windward side of the house.
- What fixes it
- Raise the heat, open the faucet, and run a space heater in the room at a safe distance from the wall. If it won't thaw, a plumber can thaw it or open the wall. It may need insulation or rerouting.
3. Crawl space or unheated basement
- How to tell
- Several fixtures are dry at once, or the whole house is. Exposed pipes may have frost on them, and a crawl space vent or door may be open or broken. If the whole house is dry, ask a neighbor first: it may be the water supply.
- What fixes it
- Close crawl space vents and doors, and warm the exposed pipes with a hair dryer or heating pad. Insulate those pipes before the next cold snap.
4. Pipes in a garage or attic
- How to tell
- Fixtures fed by pipes that run through an unheated garage, an attic or the floor over a garage are dry. Often after the garage door was left open.
- What fixes it
- Keep the garage door closed, warm the pipe where you can reach it, and add insulation or UL-listed heat tape to that run.
5. Pipe has already split
- How to tell
- Water appears as it thaws: dripping, spraying, a wet spot on a wall or ceiling, or water on the floor. You may see a bulge or a lengthwise split in the pipe.
- What fixes it
- Shut off the main right away and call a plumber to replace the damaged section. Freezing can split a pipe in more than one place, so have the whole run checked.
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What you can safely try first
- 1Find the main water shut-off and make sure it turns before you thaw anything. It's usually where the water line enters the house, in a basement, crawl space, garage or utility closet, or outside near the meter.
- 2Open the faucet that isn't working, hot and cold, so melting ice can flow out and pressure can escape.
- 3Open the cabinet doors under sinks on outside walls and turn the heat up a few degrees.
- 4Trace the pipe back from the faucet and look for frost or the coldest spot. Warm it with a hair dryer, heating pad or towels soaked in hot water, starting nearest the faucet and working back toward the ice.
- 5For a pipe you can't reach, run a space heater in the room at least 3 feet from anything that can burn, away from water, and never unattended.
- 6Keep going until full pressure returns, then check along the pipe for drips and check every other faucet in the house.
When to call a pro
- A pipe has split, or water shows up in a wall, ceiling or floor as it thaws.
- You can't find or reach the frozen section.
- The water doesn't come back after an hour or so of steady, gentle heat.
- The same pipe freezes every cold snap.
What it costs
| Job | DIY parts | Pro, installed |
|---|---|---|
| Thaw a frozen pipe | $0–$30 | $150–$600 |
| Foam insulation for exposed pipes | $10–$60 | $150–$600 |
| UL-listed heat tape on an accessible pipe | $30–$100 | $150–$500 |
| Repair a burst pipe you can reach | Not recommended | $200–$1,000 |
| Repair a burst pipe inside a wall or ceiling, plus drywall | Not recommended | $600–$2,500+ |
| Water damage cleanup and drying | — | $1,000–$5,000+ |
Ballpark US ranges as of September 28, 2026. Your region, access and the specifics of your home can move these a lot. Get two or three quotes for anything over a few hundred dollars.
What to tell the pro
The [kitchen / bathroom / laundry / whole house] has had [no water / only a trickle] since the temperature dropped to about [temperature]. I think the pipe froze [under the sink on an outside wall / in the crawl space / in the garage / inside a wall]. I've [opened the faucet / used a hair dryer / run a space heater] for [time]. I [do / don't] see water leaking, and I [have / haven't] shut off the main. If a pipe has split, does your price include opening the wall, and who handles the drywall? Can you insulate or reroute it so it doesn't freeze again?
Questions people ask
How do I know if my pipes are frozen?
No water or only a trickle from a faucet during freezing weather is the main sign, especially at a sink on an outside wall. You may also see frost on an exposed pipe or a bulge in it. If only one fixture is dry, the frozen spot is on the pipe that feeds it.
How do I thaw a frozen pipe safely?
Open the faucet, then warm the pipe with a hair dryer, heating pad or towels soaked in hot water, starting nearest the faucet and working back. Keep going until full pressure returns. Never use a torch, open flame or propane heater, and keep electric heaters and hair dryers away from standing water.
What should I do if a frozen pipe bursts?
Shut off the main water valve right away, then turn off the water heater and switch off the breaker for any area where water is near wiring or outlets. Call a plumber, move belongings out of the water, and photograph the damage before cleanup for your insurance claim.
How do I keep pipes from freezing?
Let faucets on outside walls drip on the coldest nights, open the cabinet doors under sinks, and keep the heat at 55°F or higher, even when you're away. Disconnect garden hoses and shut off and drain outdoor faucets before the first freeze. Insulate exposed pipes in crawl spaces, garages and attics, and use UL-listed heat tape, installed exactly as its instructions say, on pipes that freeze anyway.
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General guidance, not a substitute for a licensed professional who can see the problem in person. If you smell gas, see sparks or smoke, or anyone is hurt, leave the area and call 911.