How to Unfreeze Pipes

By Amanda Lutz Updated June 17, 2024

Even if you love winter, nobody loves dealing with frozen pipes. This can happen during extremely cold weather, especially if you’re not regularly running the water, or certain areas of your home are unheated. Frozen pipes prevent your drains from working, blocking your water supply. If you don’t quickly thaw them, they can burst—and the resulting damage may require extensive work and money to address. 

Thawing water pipes quickly is essential to restoring your water flow and avoiding burst pipes. But locating the frozen sections and resolving the problem can be challenging. Read our guide to learn how to locate and thaw frozen pipes, how to prevent refreezing, and when to call a plumber. 

How to Locate Frozen Pipes

All of your pipes will rarely freeze at once. It’s typically local to whatever faucet isn’t running water. Before pinpointing the exact location, you must confirm that a frozen pipe is indeed the problem. You can do so with the following steps: 

Thawing Methods

Sometimes, thawing pipes is an easy, do-it-yourself (DIY) job. There are two basic ways to do this: one requires encouraging water movement, while the other works by applying direct heat. Using these methods simultaneously tends to deliver the most effective results. The process can take several hours, and it is essential to avoid using high-heat devices that can damage pipes or start a fire.

Encouraging Water Flow

If you’ve ever noticed that ponds freeze over during cold weather while rivers are unaffected, you’ve witnessed how water movement can prevent freezing. Trickling water passing through your water line can similarly impact the ice in your pipes. Begin by opening all affected water faucets to allow as much water movement as possible. If you’re still getting a small trickle of water, it can help prevent the pipe from fully freezing and even melt existing ice. Even if pipes are fully blocked, opening the faucet relieves pressure that can help you avoid bursting a pipe. 

After turning on the faucets, ensure that exposed pipes get as much additional heat as possible. Open any cabinet doors beneath sinks and doors that could block heat flow. Place a fan or space heater nearby to circulate warm air toward the area of the frozen pipe. This approach requires patience, as the thawing process can take several hours.

Heat Application Techniques

While your faucets are turned on, apply heat near the frozen pipe sections to speed up the melting process. There are several safe heat sources for applying heat to frozen pipes. You may even be able to apply a combination of heating methods for improved results. No matter what you use, avoid using open flames and never leave heating devices unattended. Use one or more of these heat sources to warm frozen pipes: 

Thawing pipes with a direct heat source requires beginning at the affected faucet and working your way back toward the frozen section. Before starting the thawing process, open the affected faucets to encourage water flow. 

Frozen pipes are often exposed, making them easily accessible for thawing. Working slowly, apply heat to any exposed areas of the pipe. The frozen area may be bulging or have visible frost on the outside. Consider setting up a space heater nearby and working with a direct heat source to thaw the area. Exercise patience and avoid overheating the pipe so you don’t damage it. 

Water will most likely emerge from your faucet as a trickle as the pipes begin to thaw. While this is an early signal of success, don’t stop applying heat until full pressure is restored. 

How to Prevent Refreezing

Once you have restored your water flow, you can take steps to avoid similar problems in the future. Just as you might winterize your home, there are ways you can winterize your vulnerable water pipes to protect them in freezing temperatures. 

When to Call a Plumber

Unfortunately, you may not always have adequate plumbing experience to thaw your frozen pipes independently. While you might be tempted to wait for the pipes to thaw, doing so could result in burst pipes, water damage, and more issues with your plumbing system. Contacting a professional plumber when the following situations occur could help you save money in the long run and avoid a home improvement project you didn’t plan for:

If any of these apply, you must find a qualified professional to thaw your pipes and repair any related damage. Explain to your prospective plumber that time is of the essence to avoid extensive water damage, and ask them questions like the following to make sure they’re right for the job:

Our Recommendation

Frozen water pipes can cut off part or all of your water supply and prevent your drains and toilets from working. If you don’t thaw them promptly, pipes can burst and cause expensive water damage to your home. Burst water pipes can be expensive to fix and may leave you without water for even longer. You can use a combination of methods to thaw your water pipes. However, it’s best to contact a plumbing professional if your efforts are ineffective or you’re unsure of your abilities. After you’ve thawed your pipes, taking precautionary measures to prevent them from refreezing is vital.

How to Unfreeze Pipes FAQ

At what temperature do pipes freeze?

The temperature at which pipes freeze could depend on your location and how your pipes are insulated. While pipes are at risk of freezing at 32 degrees Fahrenheit, frozen pipes are much more common when the temperature reaches about 20 degrees Fahrenheit.

Can you pour hot water down the drain to unfreeze pipes?

If your drain pipe is frozen, you can thaw it with hot or boiling water. However, if this doesn’t work, the water will cool and freeze, adding to the clog. Pour slowly to prevent overflowing if you try this method.

How long does it take for pipes to unfreeze?

How long it takes pipes to unfreeze depends heavily on the weather and your thawing method. Pipes can take several days to thaw on their own, and it’s best not to leave them unattended in case they leak or burst. You can thaw your pipes within a few hours using the right thawing techniques.

Will polyvinyl chloride (PVC) pipes burst if frozen?

PVC pipes can burst if frozen since ice swells as it freezes, and the plastic pipes can expand and shrink. However, these pipes don’t always burst, especially when they’ve been frozen for a short time.