How to Prevent Frozen Pipes (And What to Do If They Freeze)

Updated March 22, 2026 · Expert-verified answer

Quick Answer

Prevent frozen pipes by insulating exposed pipes ($1–$3 per linear foot), keeping your thermostat at 55°F+ even when away, opening cabinet doors under sinks on cold nights, and letting faucets drip during extreme cold. If pipes freeze, never use an open flame — use a hair dryer, heat lamp, or towels soaked in hot water to thaw them gradually.

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Cost Breakdown

Service Low High Notes
Pipe insulation (DIY) $1/ft $3/ft Foam sleeves, easy install
Heat tape/cable $30 $100 For high-risk pipes
Professional pipe insulation $200 $600 Whole-house
Frozen pipe thawing (pro) $100 $300 If accessible
Burst pipe repair $500 $2,000 Emergency rates apply
Water damage restoration $2,000 $50,000 Varies widely

Preventing Frozen Pipes

Frozen pipes are one of the most costly plumbing emergencies. A single burst pipe can cause $5,000–$50,000+ in water damage. Prevention is far cheaper than repair.

Before Winter: Preparation

  • Insulate exposed pipes in attics, crawl spaces, garages, and exterior walls. Foam pipe insulation costs $1–$3 per foot and takes minutes to install.
  • Disconnect garden hoses and close interior shut-off valves for outdoor faucets. Leave the outdoor valve open so any remaining water can drain.
  • Seal air leaks near pipes — check where pipes enter the house, around dryer vents, and near electrical wiring. Even small gaps let cold air reach pipes.
  • Know your shut-off valve location — in an emergency, you need to stop water flow fast.

During Cold Snaps

  • Let faucets drip — running water (even a trickle) through vulnerable pipes prevents freezing. Open both hot and cold lines.
  • Open cabinet doors under kitchen and bathroom sinks to let warm room air reach pipes.
  • Keep the thermostat at 55°F or higher — even when away. The cost of heating is far less than a burst pipe repair.
  • If you lose power, shut off the main water supply and open faucets to drain pipes.

If Pipes Freeze (But Have Not Burst)

  1. Turn on the faucet — even if nothing comes out, leave it open so melting ice can drain
  2. Apply gentle heat using a hair dryer, heat lamp, heating pad, or towels soaked in hot water
  3. Start from the faucet side and work toward the frozen area
  4. Never use a blowtorch, propane heater, or open flame — fire risk and pipe damage
  5. Check all faucets — if one pipe froze, others may have too

If a Pipe Bursts

  1. Shut off the main water supply immediately
  2. Open all faucets to drain remaining water
  3. Call a plumber for emergency repair
  4. Document damage for insurance (photos/video)
  5. Begin water extraction and drying to prevent mold (mold starts in 24–48 hours)

Related Questions

At what temperature do pipes freeze?

Pipes can begin to freeze at 20°F (-7°C), but the risk increases significantly below 15°F. Wind chill, pipe location (exterior walls, attics, crawl spaces), and insulation all affect the freezing point. Pipes in heated interior spaces rarely freeze.

How long does it take for pipes to freeze?

Uninsulated pipes in exposed areas can freeze in as little as 6 hours at 20°F. Well-insulated pipes in heated spaces may never freeze even in extreme cold. The duration depends on temperature, wind, insulation, and water flow.

Will my homeowner's insurance cover frozen pipe damage?

Most policies cover sudden water damage from burst pipes IF you maintained adequate heat in the home. If you left the home unheated and pipes froze, the claim may be denied. Check your policy for specific winter maintenance requirements.