How to Keep Pipes From Freezing (and What to Do If They Do)

To keep pipes from freezing, keep your home heated to the same temperature day and night, let cold water drip from faucets on outside walls during very cold nights, open cabinet doors under sinks, and insulate pipes in unheated areas. Before winter, shut off and drain outdoor faucets and bring in garden hoses.

A frozen pipe can burst and pour hundreds of gallons of water into your home. A few cheap steps now can save you a big repair bill later.

Why frozen pipes burst

Water expands when it freezes. When ice forms inside a pipe, it pushes water pressure up between the ice and the closed faucet. That pressure can split the pipe. Often you do not find out until the ice melts and water starts spraying.

Which pipes freeze first

The American Red Cross says the pipes most likely to freeze are:

• Pipes outside the home, like outdoor faucets, sprinkler lines, and pool lines
• Pipes on outside walls with little insulation
• Pipes in unheated spaces, like garages, crawl spaces, basements, and attics
• Pipes in kitchen and bathroom cabinets on outside walls

Walk around your home and find these pipes before the first hard freeze.

When pipes are at risk

Water freezes at 32°F. But pipes inside a heated home usually do not freeze until it gets much colder outside, often around 20°F or below, especially for several hours or overnight. Wind makes it worse, because it pulls heat out of walls faster.

Watch the forecast. When a cold snap is coming, use the steps below.

10 ways to keep pipes from freezing

Before winter

1. Shut off and drain outdoor faucets. Find the shutoff valve inside your home for each outdoor faucet. Close it, then open the outdoor faucet to let the water drain out. Leave the outdoor faucet open for the winter so any water left inside has room to expand.

2. Disconnect and store garden hoses. A hose left attached traps water in the faucet, which can freeze and crack the pipe inside the wall.

3. Drain sprinkler and pool lines. Follow the maker's directions, or have a pro blow out the lines with air.

4. Insulate exposed pipes. Foam pipe sleeves from a hardware store cost just a few dollars and slide right over pipes. Use them in crawl spaces, attics, garages, and basements.

5. Seal cold air leaks. Cold drafts near pipes can freeze them fast. Seal gaps where pipes go through walls, and around dryer vents and basement rim joists. Our guide on finding air leaks in your house shows easy ways to spot them.

6. Consider heat tape for problem pipes. Heat cable or heat tape wraps around a pipe and keeps it warm. Use only products listed by a testing lab like UL, and follow the instructions closely.

During a cold snap

7. Let faucets drip. On very cold nights, let cold water drip from faucets served by exposed pipes. The Red Cross says moving water, even a trickle, helps stop freezing. If a faucet has both hot and cold, open both a little.

8. Open cabinet doors. Open the cabinets under kitchen and bathroom sinks so warm air from the room can reach the pipes. Move cleaners and chemicals up high if you have kids or pets.

9. Keep the heat steady. Keep your thermostat at the same temperature day and night during a cold spell. Skipping the usual nighttime setback may cost a little more, but it is much cheaper than a burst pipe.

10. Keep the garage door closed. If water lines run through your garage, keep the door shut to hold in warmth.

If you are going away for the winter or a trip

• Set the thermostat no lower than 55°F, as the Red Cross suggests.
• Ask someone to check your home every day or two.
• For long trips, consider shutting off the main water valve and draining the pipes by opening faucets.
• Put a smart water leak sensor under sinks and near the water heater. Many send an alert to your phone if they get wet.
• Some smart thermostats can also warn you if your home gets too cold.

How to tell if a pipe is frozen

• You turn on a faucet and get only a trickle or no water.
• You see frost on a pipe.
• A pipe has a small bulge.
• You hear odd sounds in the pipes, like gurgling, when you turn on water.

If only one faucet is slow, the frozen spot is likely near that faucet. If no faucets work, the freeze may be near where the water line enters your house, or the main line may be frozen.

How to thaw a frozen pipe safely

1. Open the faucet the pipe feeds. As the ice melts, moving water helps melt the rest.
2. Find the frozen spot. Check pipes on outside walls and in cold areas first.
3. Apply gentle heat. Use a hair dryer, an electric heating pad, or towels soaked in hot water. Start near the faucet and work back toward the frozen spot.
4. Keep going until full water pressure returns.
5. Check all other faucets. If one pipe froze, others might too.

Never use a blowtorch, propane or kerosene heater, charcoal stove, or any open flame. These can start a fire or damage the pipe. Keep electric devices away from standing water.

Call a licensed plumber if you cannot find the frozen spot, cannot reach it, or the pipe will not thaw.

What to do if a pipe bursts

1. Shut off the main water valve right away. Know where it is before winter. It is often in the basement, crawl space, or near the water heater.
2. Turn off power to any area where water is near outlets or appliances, if it is safe to reach the breaker.
3. Open faucets to drain the remaining water and take pressure off the pipes.
4. Call a plumber.
5. Dry everything fast. Use towels, fans, and a wet vacuum. Drying within 24 to 48 hours helps prevent mold.
6. Take photos for your insurance company.

After the repair, watch for slow leaks you cannot see. Our guide on signs of a leak inside your walls shows what to look for.

Low water pressure after a freeze?

If water flows again but feels weak, ice may still be in a pipe, or a small crack may be leaking. If pressure does not come back after a few hours, see our tips on fixing low water pressure in your house or call a plumber.

Winter pipe checklist

• Outdoor faucets shut off and drained
• Garden hoses disconnected and stored
• Sprinkler lines drained
• Foam insulation on exposed pipes
• Air leaks near pipes sealed
• Main water shutoff valve found and tested
• Thermostat plan for cold snaps and trips
• Leak sensors under sinks and near the water heater

The bottom line

Pipes freeze when cold air reaches them, most often outdoors, on outside walls, and in unheated spaces. Before winter, drain outdoor faucets, store hoses, and insulate exposed pipes. During a cold snap, let faucets drip, open cabinet doors, and keep the heat steady day and night. If a pipe freezes, open the faucet and warm the pipe with a hair dryer or heating pad, never an open flame. If it bursts, shut off the main water valve and call a plumber.