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Frozen or burst pipe? What to do right now, and how to prevent it

A burst pipe can release hundreds of gallons of water in a few hours. Here's what to do in the first hour, how to dry out before mold starts, and how to stop it happening again.

Reviewed October 2026

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If a pipe has burst: the first 15 minutes

  1. Shut off the main water valve. It's usually where the water line enters the house: in the basement, a crawlspace, a utility room or near the water heater. Find it now, before you need it.
  2. Turn off the power to wet areas at the breaker panel, if you can reach the panel without standing in water. If you can't, stay out and call the power company or an electrician.
  3. Open the faucets to drain the remaining water and relieve pressure.
  4. Move belongings out of the water and lift furniture onto blocks or foil.

Document, then call your insurer

Take photos and video of the water, the broken pipe and everything that got wet before you clean up. Then call your insurance company. A sudden burst pipe is usually covered by homeowners insurance, while slow leaks and damage from not heating the house often aren't. See does homeowners insurance cover flooding?

Keep receipts for emergency repairs, fans, dehumidifiers and anything you buy to limit the damage.

Dry out within 48 hours

Mold can start growing within 24 to 48 hours.

  • Remove standing water with a wet/dry vacuum or a pump.
  • Run fans and a dehumidifier around the clock, with windows open if the weather allows.
  • Pull up wet carpet padding and remove soaked drywall and insulation that can't dry quickly.
  • A moisture meter tells you when walls and floors are really dry, not just dry to the touch.

For bigger jobs, the steps in after a flood apply here too.

Thawing a frozen pipe

If a faucet only trickles in freezing weather, a pipe may be frozen but not yet burst.

  • Keep the faucet open, so water can flow as the ice melts.
  • Warm the pipe with a hair dryer, a heating pad, or towels soaked in hot water, starting nearest the faucet.
  • Never use an open flame, a propane torch or a charcoal stove.
  • If you can't find or reach the frozen section, or it won't thaw, call a plumber.

How to keep pipes from freezing

  • Keep the heat on, set no lower than 55°F, even when you're away.
  • Let faucets drip on very cold nights, especially ones on outside walls. Moving water is less likely to freeze.
  • Open cabinet doors under sinks so warm air reaches the pipes.
  • Disconnect garden hoses and shut off and drain outdoor faucets.
  • Insulate pipes in unheated spaces like attics, crawlspaces and garages. Pipe sleeves are cheap; heat cable helps in the coldest spots.
  • Add a leak alarm near the water heater, washer and under sinks. A smart water shutoff valve can close the main automatically when it senses a leak.

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