How to Prevent Frozen Pipes in Winter
Prevent frozen and burst pipes—insulate vulnerable lines, keep heat on, and know when to shut off water before a freeze.
- Difficulty
- Beginner-friendly
- Time
- 10 minutes to read
- Est. cost
- $20–$200 (insulation and supplies)
- Season
- winter
By Keepstead Editorial Team · Published August 29, 2026 · 4 min read
Last reviewed August 29, 2026
Quick answer
Keep building heat at least 55°F (13°C) during freezes, insulate pipes in crawl spaces and garages, seal drafts near plumbing walls, and open cabinet doors under sinks on exterior walls during severe cold. Locate your main water shutoff before an emergency. Add tasks to your winter checklist.
Frozen pipes block water flow and can burst when ice expands—often causing major water damage. Prevention focuses on keeping pipes above freezing and reducing exposure in vulnerable spots. Most steps are homeowner-friendly; burst pipe cleanup and hidden leak repair may need a plumber.
Prevention checklist (priority order)
- Locate your main water shutoff and confirm it turns off—before a freeze, not during a burst
- Keep thermostat at least 55°F (13°C) when away during freezing weather
- Insulate exposed pipes in crawl spaces, garages, and along exterior walls
- Disconnect garden hoses and drain exterior hose bibs where possible
- Seal drafts at exterior-wall plumbing chases and doors—see weatherstripping
- Open cabinet doors under sinks on exterior walls during severe cold (remove hazardous cleaners from child/pet reach)
- Allow a slow drip on vulnerable fixtures only when recommended for your climate and after shutoff location is known
Where pipes freeze first
- Exterior walls behind kitchen and bath sinks
- Crawl spaces and unheated basements
- Garages with hose bib supply lines
- Vacant or second homes with heat turned down
- Attics with HVAC condensate or routing errors
Walk these areas before cold season and note uninsulated copper, PEX, or CPVC runs.
Keep heat in the building
- Maintain thermostat at least 55°F when away during freezing weather—higher if pipes have frozen before.
- Open interior doors so heat reaches rooms with plumbing on exterior walls.
- During severe cold, open cabinet doors under sinks so room air warms pipes (remove hazardous cleaners from reach of children and pets).
Why heat matters: insulation slows loss; heat source prevents pipe temperature from dropping below freezing.
Insulate vulnerable pipes
Use foam pipe insulation sized to pipe diameter on runs in crawl spaces, garages, and along exterior walls. Seal gaps at penetrations with appropriate caulk or foam—coordinate with weatherizing doors to reduce cold air infiltration.
Heat tape or heat cable products exist for extreme exposures—follow manufacturer instructions and electrical safety; some installations belong to an electrician.
Outdoor faucets and hose bibs
- Disconnect garden hoses before freeze season.
- Shut off and drain interior supply to exterior bibs if you have isolation valves.
- Install frost-free bib models or insulated covers per product guidance.
Include bib checks on your winter home maintenance checklist.
Before you leave town
- Set heat to safe minimum—not off.
- Ask someone to check the home during extended cold snaps.
- Know where the main water shutoff is and show it to a house sitter.
If pipes are already frozen
- Keep the faucet open—flow may resume as ice melts.
- Apply gentle heat to the frozen section (hair dryer, heat lamp, towels soaked in warm water)—never open flame on or near pipes.
- If you cannot locate the freeze, or pipe is split, shut off main water and call a licensed plumber.
Do not wait for a split—water damage spreads quickly.
Thawing and repair limits
DIY: slow thaw with safe heat on exposed pipes you can reach.
Call a plumber for:
- No water after careful thaw attempts
- Visible split or spray
- Frozen pipes inside walls or slab
- Recurring freezes despite insulation
See when to call a plumber vs DIY for broader plumbing boundaries.
Link to seasonal maintenance
Frozen pipe prevention fits winter tasks and annual planning—pair with furnace checks and water heater maintenance so systems run reliably in cold months.
Frequently asked questions
- At what temperature do pipes freeze?
- Pipes can freeze when temperatures stay below freezing long enough—especially in unheated spaces. Wind chill, poor insulation, and pipes on exterior walls increase risk before a specific outdoor number applies everywhere.
- Should I let faucets drip in freezing weather?
- A slow drip on vulnerable fixtures can relieve pressure if ice forms. Focus on pipes along exterior walls and in crawl spaces. Know where your main shutoff is first—see our shutoff guide.
- Will pipe insulation alone prevent freezing?
- Insulation slows heat loss but does not add heat. In very cold unheated areas, combine insulation with maintaining building heat or rerouting pipes away from exterior walls.
Sources & references
Related guides
Winter Home Maintenance Checklist for Homeowners
Cold-weather prep: heating checks, freeze protection, safety devices, and exterior tasks—prioritized for homeowner-safe work.
How to Find Your Main Water Shutoff Valve
Locate your home's main water shutoff—basement, crawl space, meter, or street—and practice turning it off before a leak emergency.
When Should You Call a Plumber Instead of DIY?
Toilet running, slow drain, or leak at the wall? See which plumbing jobs are safe DIY—and which need a licensed plumber before you start.
How to Maintain a Water Heater: Homeowner Checklist
Maintain tank and tankless water heaters—flush sediment, test relief valve, check anode, and know when a plumber should take over.
This guide is for general informational purposes. Conditions vary by home, local codes, and equipment. See our disclaimer.