How to Prevent and Thaw Frozen Pipes: Dripping Faucets, Safe Thawing Methods and What to Do If a Pipe Bursts

Quick answer: to prevent frozen pipes, keep the heat on and steady day and night (the American Red Cross says no lower than 55°F if you will be away), open kitchen and bathroom cabinet doors on outside walls so warm air reaches the plumbing, let a cold faucet served by exposed pipes drip, and disconnect and drain outdoor hoses. If a faucet only trickles, a pipe may be frozen: keep the faucet open and warm the pipe with a hair dryer, heating pad or towels soaked in hot water, never an open flame. If a pipe bursts, shut off the main water valve, keep away from electrical hazards and call a plumber and your landlord.

Water expands as it freezes. Inside a pipe, that expansion builds pressure that can split copper, plastic or steel lines. The damage often shows up only when the ice melts and water starts pouring out of a crack inside a wall or ceiling.

City homes face particular risks. Pipes may run along exterior walls in older buildings, through unheated basements, garages or crawl spaces, or into kitchens on the coldest side of a building. When heat fails during a winter storm or outage, the risk climbs quickly. This guide draws on guidance from the American Red Cross, Ready.gov and the National Weather Service. It is part of our severe weather preparedness guide.

Sources: American Red Cross, “Frozen Pipes” and winter storm safety guidance; Ready.gov Winter Weather and Power Outages; National Weather Service winter safety and wind chill information; Insurance Information Institute guidance on documenting water damage claims; local building and plumbing guidance on main water shutoff valves. Check your lease, building rules and local codes for anything you plan to change. Checked October 2026.

Which Pipes Freeze First

The American Red Cross identifies the pipes most at risk:

• Pipes exposed to severe cold, such as outdoor hose bibs, swimming pool supply lines and water sprinkler lines.
• Water supply pipes in unheated interior areas, such as basements, crawl spaces, attics, garages and kitchen cabinets.
• Pipes that run against exterior walls with little or no insulation.

In apartments, add a few common trouble spots: sinks on an outside wall, plumbing near drafty windows, and units over open parking garages or unheated lobbies. Ground-floor and top-floor units often run colder. If your building has had frozen pipes before, the super or management office usually knows exactly where.

Before a Cold Snap: Prevention Steps

Most frozen pipes are preventable with a few steps taken before temperatures plunge. These come from Red Cross guidance unless noted.

Outdoors and in unheated spaces

1. Drain and store garden hoses. Disconnect them from outdoor faucets.
2. Close the indoor valve that supplies an outdoor hose bib, then open the outside faucet to let water drain. Keep it open so trapped water can expand without breaking the pipe.
3. Drain sprinkler and pool supply lines following the manufacturer’s or installer’s directions. Do not put antifreeze in these lines unless directed, since it is harmful to people, pets, wildlife and landscaping.
4. Insulate exposed pipes in basements, crawl spaces and attics. The Red Cross suggests products made for the purpose, such as pipe sleeves or UL-listed heat tape and heat cable. Even newspaper can provide some protection on exposed pipes in an emergency.
5. Keep garage doors closed if water supply lines run through the garage.

Inside your home

• Open kitchen and bathroom cabinet doors to let warmer room air circulate around plumbing, especially on exterior walls. Move cleaning products and chemicals out of reach of children and pets while doors are open.
• Let cold water drip from a faucet served by exposed pipes. The Red Cross notes that running water, even at a trickle, helps prevent pipes from freezing.
• Keep the thermostat at the same temperature day and night. Lowering it overnight can save a little on heating but raises the risk during extreme cold.
• Seal drafts around windows, doors and where pipes enter the building, if you are allowed to. Renters should ask the landlord before sealing anything permanent.

When you travel

If you will be away during cold weather, the Red Cross advises leaving the heat on and set to a temperature no lower than 55°F. Ask a neighbor or the building manager to check the unit if a deep freeze is forecast, and know how to shut off water to your unit before you leave.

Know Where Your Shutoff Valve Is

When a pipe bursts, minutes matter. Find your shutoff before you need it.

Home type	Where shutoffs are often found
Single-family house	Main valve near the water meter, often in a basement, crawl space, utility room or at the front foundation wall; some homes have a curb valve at the street that only the utility should use
Townhouse or row house	Near the meter or where the water line enters, often in a basement or utility closet
Apartment or condo	Unit shutoff valves may be under sinks, behind an access panel, in a utility closet or near the water heater; some buildings only have shutoffs controlled by building staff
Individual fixtures	Small valves under sinks and behind toilets that stop water to that fixture only

Turn the valve once or twice a year to make sure it moves. Tag it so anyone in the household can find it. Our guide on how to shut off utilities covers water, gas and electricity shutoffs in more detail.

Signs a Pipe Has Frozen

The most common sign is simple: you turn on a faucet and only a trickle comes out, or nothing at all, during freezing weather. Other clues include:

• Frost visible on an exposed pipe
• A section of pipe that feels very cold or looks bulged
• Odd smells from a drain, since a blocked line can push odors back up
• One faucet working while another nearby does not

If you suspect a frozen pipe, keep the faucet open. As the ice melts, flowing water helps melt the rest, and an open faucet relieves pressure.

How to Thaw a Frozen Pipe Safely

The American Red Cross gives a clear sequence.

1. Keep the faucet open. Water will begin to flow as the frozen area melts.
2. Apply heat to the frozen section with an electric heating pad wrapped around the pipe, an electric hair dryer, a portable space heater kept away from flammable materials, or towels soaked in hot water wrapped around the pipe.
3. Never use an open flame. The Red Cross specifically warns against using a blowtorch, kerosene or propane heater, charcoal stove or other open-flame device, which can start a fire or damage the pipe.
4. Keep heating until full water pressure returns.
5. Call a licensed plumber if you cannot find the frozen area, cannot reach it, or cannot thaw it.
6. Check all other faucets in your home. If one pipe froze, others may have too.

Electric devices and water do not mix. Keep hair dryers, heating pads and space heaters away from standing water, and do not use them if you are standing in water. If you use a space heater near pipes, keep it at least 3 feet from anything that can burn, plug it directly into a wall outlet and never leave it running unattended.

Pipes inside walls

If the frozen section is behind a wall or ceiling, raise the heat in the room and open cabinet or access doors to let warm air in. The Red Cross also mentions using an infrared lamp or space heater aimed at the wall area, with care. Tearing into a wall to reach a pipe is usually a job for a plumber, and in an apartment it requires the landlord’s permission.

If a Pipe Bursts

A split pipe can release a large amount of water quickly. Act in this order.

1. Shut off the water at the main valve or the unit shutoff. If you cannot find it or it will not turn, call building staff or an emergency plumber immediately.
2. Stay away from electrical hazards. If water is near outlets, appliances or the electrical panel, do not touch them while standing in water. If you can reach the breaker panel safely from a dry spot, shut off power to affected areas; otherwise call an electrician or the utility.
3. Call a plumber, and in an apartment, notify the landlord or super right away. Units below yours may be affected too.
4. Move belongings out of the water and start removing water with towels, mops or a wet-dry vacuum once it is safe.
5. Open cabinets and run fans to help drying, and keep the heat on.
6. Document everything before cleanup where possible: photos and video of the damage, the pipe and affected belongings.

Insurance and Documentation

Water damage claims depend heavily on the details of your policy. The Insurance Information Institute notes that standard homeowners policies generally cover sudden and accidental water damage, such as a burst pipe, but not damage from gradual leaks or from failure to maintain heat in some situations. Renters insurance can cover your belongings, while the building owner’s policy typically covers the structure.

To help a claim:

• Report damage promptly to your insurer and landlord.
• Keep receipts for emergency repairs, drying equipment and temporary housing.
• Save damaged items or photos of them until an adjuster sees them, if possible.
• Keep a record of when the heat failed or the pipe froze and whom you contacted.

Our guide on renters insurance and home inventories for disasters explains how to document belongings before something goes wrong.

Frozen Pipes During a Power Outage

When a winter outage shuts off heat, the protective steps above get harder. Ready.gov and the Red Cross suggest these priorities:

• Keep one or more faucets dripping, especially on exterior walls.
• Keep cabinet doors open and interior doors open to share whatever heat remains.
• Use safe heat sources only. Never heat a home with a gas oven, grill or camp stove, and run generators only outdoors away from windows and doors.
• Know when to drain the system. In a prolonged outage with dangerously low indoor temperatures, some homeowners shut off the main valve and drain pipes by opening faucets at the lowest point. In apartments, follow building staff instructions.
• Store water before the storm in case lines freeze anyway. Our guide on preparing for a winter power outage lists what to set aside.

Renters: Your Role and the Landlord's

In most cities, landlords are responsible for maintaining heat and plumbing, and many local codes set minimum indoor temperatures during the heating season. Tenants usually help by keeping the heat on, reporting problems quickly and following building instructions during cold snaps. If heat fails, report it in writing and contact your local housing or code enforcement office if it is not restored. Check your lease for anything it says about frozen pipes and unit temperature while you are away.

Frequently Asked Questions

At what temperature do pipes freeze?

Water freezes at 32°F, but pipes do not usually freeze the moment the outdoor temperature reaches that level. Risk rises with longer and deeper cold, wind, and how exposed or uninsulated the pipe is. Prevention steps are worth taking whenever a hard freeze is forecast.

Should I let my faucets drip overnight?

For faucets served by exposed pipes, yes. The American Red Cross says running water, even at a trickle, helps prevent pipes from freezing.

Can I use a hair dryer to thaw a frozen pipe?

Yes. The Red Cross lists an electric hair dryer as a safe option, along with heating pads, space heaters kept away from flammables, and hot, wet towels. Keep the faucet open and never use an open flame.

What temperature should the heat be set to during winter travel?

The American Red Cross advises leaving the heat on and set no lower than 55°F.

What should I do first if a pipe bursts?

Shut off the water at the main or unit valve, stay clear of electrical hazards, then call a plumber and your landlord or building manager.

The Bottom Line

Frozen pipes are mostly a prevention problem. Keep the heat steady, open cabinets on cold walls, let exposed lines drip, drain outdoor faucets and know where your shutoff valve is. If a pipe freezes, thaw it gently with electric heat or hot towels and an open faucet, and if it bursts, shut off the water first and call for help.