How to Prevent Frozen Pipes This Winter

At What Temperature Do Pipes Freeze or Burst?

Water freezes at 32F, but a pipe rarely bursts right at that point. Consumer Reports and other field test data generally place the real danger zone for exposed, uninsulated pipes below about 20F, though pipe material, insulation, and wind exposure all change the real number.

A pipe bursts when trapped water pressure builds between an ice blockage and a closed faucet. See why pipes actually burst for the full mechanism.

Treat this table as a general guide, not an exact prediction.

How to Prevent Frozen Pipes: Which Pipes Are Most at Risk?

Pipes running through unheated or poorly insulated spaces are most likely to freeze: exterior walls, attics, crawl spaces, garages, and cabinets under kitchen or bathroom sinks.

Work through this checklist room by room before the first hard freeze.

• Kitchen and bathroom cabinets: pipes under a sink that backs onto an exterior wall.
• Garage: any water line, sprinkler backflow valve, or washing machine hookup.
• Attic: supply lines feeding an upstairs bathroom or a rooftop unit.
• Crawl space and basement rim joists: exposed pipes near vents or uninsulated foundation walls.
• Exterior walls: any plumbing run built into an outside wall, common in older additions.
• Outdoor hose bibs, spigots, and well or pump houses, each covered below.

If a pipe here has already stopped running or looks frosted over, see how to tell if a pipe is already frozen.

What Should You Set Your Thermostat To Prevent Frozen Pipes?

Keep your thermostat no lower than 55F, even overnight or while away. The air inside an exterior wall cavity, where many pipes run, gets colder than the room air your thermostat measures.

The American Red Cross tells homeowners leaving for cold weather to leave the heat on at a temperature no lower than 55F, and IBHS, the insurance industry's own research group, sets that same 55F floor even when no one is home.

The Red Cross adds one point: keep the thermostat at the same temperature day and night instead of lowering it, since a higher heating bill costs less than a burst pipe repair.

Not every source agrees. The Insurance Information Institute (Triple-I) recommends a 65F minimum in its own guidance.

Many homeowners policies also expect you to take reasonable steps to protect the property, such as keeping the heat on, so it is worth checking how homeowners insurance treats a burst pipe claim before winter arrives.

Treat 55F as the general safety floor. If your home is unusually exposed, sits in a very cold climate, or your policy sets a higher minimum, follow the stricter number and check your policy's wording.

Should You Let a Faucet Drip to Prevent Frozen Pipes?

Yes. Letting a faucet drip keeps water moving through a pipe that could otherwise freeze solid, and opening cabinet doors under a sink lets warm air reach pipes in an exterior wall.

The American Red Cross advises letting cold water drip from a faucet served by exposed pipes during severe cold, even at a trickle, with the cabinet doors open below it.

The drip does not need to be heavy; a slow trickle is generally considered enough, though this rate is widely repeated guidance, not one agency's exact number.

Drip the faucet fed by your most exposed pipe run, such as one on an exterior wall, not just any faucet.

How Do You Insulate Pipes to Prevent Freezing?

Wrap any exposed pipe in an unheated space in a foam sleeve or fiberglass wrap, and pick a thickness rated for your climate. Check the product label for its R-value rather than assuming one product fits every spot.

The American Red Cross recommends adding insulation to exposed pipes in attics, basements, crawl spaces, and garages, and checking under kitchen and bathroom cabinets for pipes that need it too. Cited minimums run around R-3, climbing to roughly R-4 to R-8 for the coldest spots; typical foam sleeves run about R-2 to R-4 by thickness.

Where people forget to insulate

Elbows, shutoff valves, and the last foot of pipe at an exterior wall or rim joist are easy to skip, and that segment is often the coldest point in the run.

If a pipe already froze, apply gentle heat rather than a flame. See our guide on how to thaw a frozen pipe safely.

Is Heat Tape Safe for Preventing Frozen Pipes?

Heat tape can keep a pipe from freezing, but the CPSC ties it to roughly 3,300 fires and about 20 deaths a year, almost always from old, uncertified, or improperly installed tape.

The U.S. Consumer Product Safety Commission estimates about 3,300 fires, 20 deaths, and 150 injuries occur annually from heat tapes and cables, mostly from improper installation or aging tape.

• Use only UL listed or UL certified heat tape or cable.
• Plug it into a GFCI protected outlet.
• Never let the cable overlap or cross itself.
• Never cover it with insulation unless the manufacturer allows a specific non flammable type.
• Replace uncertified tape, or tape older than 3 years, before winter.

See our guide on preventing pipes from bursting for other reasons if you would rather avoid an electrical device.

How Do You Protect Pipes in a Garage or Crawl Space?

Keep the garage door closed as much as possible during freezing weather. Insulate or heat-tape any exposed pipe run in the garage or crawl space, and cover crawl space vents to cut wind exposure.

An open garage door or crawl space vent lets the coldest outside air reach exposed pipes directly, which is why closing doors and covering vents is standard advice.

Treat a garage washing machine hookup or sprinkler valve the same as any other exposed pipe on the checklist above.

How Do You Winterize Outdoor Hose Bibs and Spigots?

Disconnect and drain garden hoses before the first hard freeze. Shut off the interior valve feeding the outdoor spigot and drain the line, then cover the spigot with an insulated cover.

1. Disconnect and drain every garden hose before the first hard freeze.
2. Find and shut off the interior shutoff valve for that spigot, if your home has one.
3. Open the spigot to let remaining water drain out, then leave it open.
4. Cover the spigot with a foam or insulated faucet cover for the season.

A spigot left connected to a full garden hose cannot drain, a common reason an outdoor line splits.

How Do You Protect Well Water Pipes and Pump Houses From Freezing?

Well pipes need the same insulation and heat tape protection as any exposed city supplied pipe, plus attention to the pump housing, since a pump that loses heat or power can freeze and crack.

Insulate the well pipe run like any exposed pipe, and insulate or gently heat the pump house. If the home will be vacant, have someone confirm the pump house heat source, if it has one, still works during the coldest stretch.

Well systems rarely get separate advice from restoration guides, even though a frozen pump house can leave a household with no water until it thaws or is repaired.

What Should You Do Before Leaving Home for Winter?

For a short trip, leave the thermostat at 55F or higher and a cabinet door open. For a home sitting vacant for the season, also shut off and drain the main water supply or have someone check the house regularly.

A season-long closure starts with knowing where that valve is. See our guide to find your main water shutoff valve.

Is Preventing Frozen Pipes Cheaper Than Repairing a Burst One?

Yes, by a wide margin. A few dollars of foam pipe insulation or a roll of heat tape costs far less than a burst pipe repair, which commonly runs about $200 to $3,000 or more before cleanup.

That range comes from secondary industry sources, not one confirmed primary source, so treat it as illustrative. See our full breakdown of typical burst pipe repair cost for cleanup and drywall costs too.

The Insurance Information Institute's own claims data puts water damage and freezing as the second most common homeowners insurance claim category, with about 1 in 60 insured homes filing one of these claims in a given year, though it is not among the costliest per claim.