01In short
Pipes freeze where cold air reaches them: exterior walls, crawlspaces, garages, unheated extensions, kitchen sinks on outside walls and outdoor faucets. Ice in the pipe raises pressure, and the pipe can split. The leak often appears only when the ice melts.
02Common signs
- No water, or a trickle, from one or more taps in cold weather
- Frost on an exposed pipe
- Bulging or cracked pipe
- Water appearing after a cold snap ends
- Strange smells from drains (frozen drain or vent)
03Possible causes
| Location | Why | Prevention |
|---|---|---|
| Exterior walls | Little insulation between pipe and outside | Open cabinet doors; insulate; let a faucet drip in severe cold |
| Crawlspaces & garages | Unheated space | Insulate pipes; heat tape where suitable |
| Rear extensions & additions | Often poorly insulated | Insulate; keep heat on |
| Outdoor faucets | Water left in the line | Shut off and drain before winter, or use frost-free faucets |
| Vacant or seasonal homes | Heat off or low | Keep heat on or have plumbing winterized |
04What you can safely check
- Which taps have no water: that narrows down the frozen section
- Exposed pipes for frost, bulges or cracks
- That the heat is working in the area
- Use an open flame, torch or propane heater on a pipe
- Leave a space heater unattended or near flammable materials
- Use electrical devices if there is standing water
- Thaw a pipe without knowing where your main shutoff is
05When to call a plumber
- You can't find or reach the frozen section
- The pipe has split or is leaking
- Several pipes froze, or it keeps happening
- Drains or vents froze
A plumber thaws the line safely, repairs split sections and can add insulation, reroute exposed pipes or install frost-free outdoor faucets. See pipe repair and emergency plumbing.
06By building type
- Brownstones & rowhouses
- Rear extensions and cellar walls at the front are common freeze points.
- Two- & three-family houses
- Basements and exterior kitchen walls; vacant units are high risk.
- Suburban houses
- Garages, crawlspaces and outdoor faucets.
- Shore & seasonal homes
- Keep heat on or winterize: shut off, drain and protect fixtures.
07Local considerations
Cold snaps in December through February cause most freeze calls across NYC, Long Island, Westchester and New Jersey. In NYC rentals, owners must provide heat during the heating season; if your apartment is cold enough for pipes to freeze, tell the building and contact 311.
08Frequently asked questions
Should I let faucets drip in a cold snap?
A slow drip on faucets fed by exposed pipes reduces the chance of freezing. Open cabinet doors under sinks on outside walls too.
How do I know if the pipe burst?
Look for splits or bulges, and watch for water once it thaws. Check the water meter with all taps off: if it moves, there's a leak.
Who pays for a burst pipe in a rental?
Usually the landlord repairs the pipe. Damage to your belongings is a renter's insurance question.
09Related
Services that fix this
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Sources & review
Last reviewed . General information, not legal or engineering advice. Rules change and individual buildings differ.