A frozen pipe may thaw on its own as temperatures rise, but the risk is that it has already burst or will burst when it thaws. A frozen pipe can crack or split from the pressure of expanding ice, and the burst may not be visible until the ice melts and water flows freely. If you suspect a frozen pipe, do not wait for it to thaw on its own — shut off the main water valve and call for help.

What you need to know

It may thaw, but it may have already burst. Do not wait — shut off the water and call for help.

In detail

A frozen pipe can thaw on its own as temperatures rise, but this is not something to wait for. When water freezes, it expands, which can crack or split the pipe. The crack may not be obvious while the pipe is frozen because the ice blocks the flow. When the pipe thaws, water can pour out of the split, causing sudden and severe flooding.

For this reason, if you suspect a pipe is frozen — you turn on a faucet and little or no water comes out — you should shut off the main water valve immediately. This way, if the pipe has cracked, the water is already off when it thaws, limiting the damage. You can then call a plumber or restoration provider.

Do not use an open flame or high heat to thaw a pipe, as this can damage the pipe or start a fire. A hair dryer on low heat applied to the exposed pipe section can help, but if you are unsure where the freeze is or the pipe is behind a wall, professional help is safer. In a Chicago winter, frozen pipes are common and fast action prevents burst-pipe flooding.

What not to do

Do not wait for a frozen pipe to thaw on its own — it may have already burst.
Do not use an open flame or torch to thaw a pipe.
Do not use high heat that can damage the pipe.

Safety

Shut off the main water valve if you suspect a frozen pipe. If there is any risk to life or safety, call 911.

Chicagoland context

Chicago winters regularly freeze pipes, especially in older buildings, exterior walls, and unheated spaces like crawlspaces and garages. Frozen pipes are a leading cause of winter water damage in Chicagoland.

Related service

This answer relates to our Frozen-Pipe Water Damage page.

Frozen-Pipe Water Damage

Will a Frozen Pipe Thaw on Its Own?