USA Expert Plumbing

How to prevent frozen pipes

By USA Expert Plumbing Editorial Team. Updated . 2 min read.

Short answer

Protect pipes in unheated spaces before winter with foam pipe insulation, seal drafts near them, and disconnect outdoor hoses. On very cold nights, keep the thermostat steady, open cabinet doors on exterior walls and let a faucet served by exposed pipes drip. If you travel, keep the heat at 55°F or higher.

In this guide
  1. Which pipes freeze first
  2. Before winter
  3. During a cold snap
  4. When you travel
  5. Warning signs a pipe is freezing
  6. Water heaters need protection too

Water expands when it freezes. In a pipe, that pressure can split copper, crack plastic and burst fittings, and the damage usually shows up when the pipe thaws and water pours out.

The steps below follow American Red Cross guidance on frozen pipes, plus manufacturer instructions where noted.

Which pipes freeze first

  • Pipes in unheated areas: crawl spaces, garages, attics and basements
  • Pipes along exterior walls, especially inside kitchen and bathroom cabinets
  • Outdoor faucets, hose bibs and irrigation lines
  • Pipes near drafts, such as around dryer vents, foundation cracks or unsealed openings

Before winter

  1. Insulate exposed pipes. Foam pipe sleeves from a hardware store fit most pipes and cost little.
  2. Seal air leaks near pipes with caulk or spray foam. A cold draft can freeze a pipe in an otherwise warm room.
  3. Disconnect hoses and winterize outdoor faucets, closing the indoor shutoff and draining the line.
  4. Drain irrigation lines following the installer's or manufacturer's instructions.
  5. Consider heat cable for pipes that cannot be insulated well. Use a product listed for the purpose and follow its instructions exactly.

During a cold snap

  • Keep garage doors closed if water lines run through the garage.
  • Open kitchen and bathroom cabinet doors so warm air reaches pipes on exterior walls. Move cleaning products out of reach of children.
  • Let cold water drip from a faucet served by exposed pipes. Moving water is less likely to freeze, and an open faucet relieves pressure if ice forms.
  • Keep the thermostat at the same temperature day and night instead of turning it down overnight.

When you travel

The Red Cross recommends leaving the heat on and set no lower than 55°F. For a longer trip, consider shutting off the main water valve and draining the lines, or asking someone to check the house daily. A smart leak detector or automatic shutoff valve can alert you, or stop the water, if a pipe bursts while you are gone.

Warning signs a pipe is freezing

  • A faucet that slows to a trickle or stops during very cold weather
  • Frost on an exposed pipe
  • A toilet that does not refill

If you see these signs, act before the pipe bursts. Our guide on how to thaw frozen pipes covers the safe ways to warm a pipe.

Water heaters need protection too

Tankless water heaters, especially outdoor models, can freeze and crack their heat exchangers. See our guide to tankless water heater freeze protection.

Common questions

At what temperature do pipes freeze?

Pipes in unheated spaces become vulnerable once outdoor temperatures fall well below freezing, and risk rises with wind, drafts and long cold spells.

Should I drip all faucets in cold weather?

Focus on faucets served by pipes on exterior walls or in unheated spaces. A slow drip of cold water is enough.

Does homeowners insurance cover frozen pipes?

Many policies cover sudden damage from a burst pipe but may exclude damage if the home was left unheated. Check your policy.

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