No Water? How to Tell if Your Pipes Are Frozen or the Water Is Off

Graphic: summary of this guide, made by our team from the cited sources.

Quick check: frozen pipe or water shutoff?

1. Ask a neighbor or check your water utility's outage page. If others on your street have no water either, the problem is likely in the public supply, not your pipes. EPCOR adds that if no fixture runs and there is no known main break in your area, a frozen service line is likely.
2. Open every faucet and flush each toilet. EPCOR suggests this to see which fixtures still run. Then read the pattern:

What you find	Most likely cause
Nothing anywhere, neighbors also out	Utility shutoff or main break
Nothing anywhere, neighbors fine	Your main shutoff is closed, or your service line or meter area is frozen
One fixture or one side of the house dry, others fine	A frozen pipe feeding that area, often on an outside wall
Cold works but hot does not	Often a frozen hot line in an outside wall or crawlspace (or a water heater issue if it is warm out)
A trickle, not full flow	The Red Cross says a trickle from a faucet in cold weather is a reason to suspect a frozen pipe

3. Check your main shutoff valve. Make sure nobody closed it. It is usually where the water line enters the house, often in a basement, crawlspace or garage, as Seattle Public Utilities describes.
4. Look and feel along exposed pipes. EPCOR says frost on a pipe or fixture is a good sign it is frozen. Under sinks on outside walls, in unheated basements, crawlspaces and garages are the usual places.

Where pipes freeze first

The Red Cross lists the pipes that freeze most often:

• Pipes exposed to severe cold, such as outdoor hose bibs, swimming pool supply lines and sprinkler lines.
• Supply pipes in unheated spaces like basements, crawlspaces, attics, garages and kitchen cabinets.
• Pipes that run along exterior walls with little or no insulation.

The same page and Seattle Public Utilities also name the spot where the water service enters the house through the foundation.

How to thaw a frozen pipe safely

These steps follow the Red Cross and Seattle Public Utilities:

1. Know where your main shutoff is before you start, in case the pipe has split.
2. Open the faucet the frozen pipe feeds. As ice melts, running water helps melt the rest.
3. Apply gentle heat to the frozen section: an electric heating pad, a hair dryer, or towels soaked in hot water. Start near the faucet and work back toward the frozen spot.
4. Never use an open flame. No torch, propane or kerosene heater, or charcoal stove. Seattle Public Utilities warns a blowtorch can make the water in the pipe boil and the pipe explode, and that open flames bring fire and carbon monoxide risks (SPU).
5. Keep electric heaters away from water. SPU says not to use electrical devices if there is standing water.
6. Keep heating until full pressure returns. The City of Toronto says thawing can take between one and six hours depending on the outside temperature and how much of the pipe is frozen.
7. Check every other faucet. The Red Cross notes that if one pipe freezes, others may too.

Call a licensed plumber if you cannot find the frozen section, cannot reach it, or cannot thaw it, as both the Red Cross and SPU advise.

After the water comes back: check for a split pipe

Water expands when it freezes, which is why frozen pipes crack (Red Cross). The leak often appears only after the ice melts.

• Look and listen along the thawed pipe for drips or spraying.
• Do the meter test from EPA WaterSense: turn off every faucet and water-using appliance, read the meter, wait, and read it again. If the meter changes at all, you probably have a leak.
• If a pipe bursts, close the main shutoff right away and call a plumber (SPU).

Preventing the next freeze

From the Red Cross:

• Let cold water drip from faucets served by exposed pipes when it is very cold. Moving water, even a trickle, helps keep a pipe from freezing.
• Open kitchen and bathroom cabinet doors so warmer room air reaches the pipes.
• Keep the thermostat at the same temperature day and night during a cold snap.
• If you travel, leave the heat on and set it no lower than 55°F.
• Drain and shut off outdoor hose bibs, pool and sprinkler supply lines before cold weather, following the manufacturer's or installer's directions.

Insulating exposed pipes in crawlspaces, attics and garages is the longer-term fix.