Can you pour hot water down a drain to thaw pipes?

Author: Aylin Crooks  |  Last update: Thursday, July 31, 2025

Heat half a gallon of water on the stove, but don't bring it to a boil. Slowly pour one cup down the drain, and let it set for a minute. Repeat the process until the frozen drain thaws. Insider Tip: Restoration professional Diana Rodriguez-Zaba advises, “Don't pour boiling water down a frozen drain.

Can I unfreeze pipes by pouring hot water down the drain?

Pipe-thawing options: There are several things you can do to thaw your home's pipes. Here's a list: Probably the most popular and safest pipe-thawing option is to use hot water.

Is it safe to pour boiling hot water down the drain?

No. Boiling water is not a proper drain clearing method nor is it for maintenance. This is especially important if you have PVC pipes, since those are wonky rated for 140F. The excessive heat can damage the pipes.

How do you unfreeze pipes quickly?

Apply heat to the section of pipe using an electric heating pad wrapped around the pipe, an electric hair dryer, a portable space heater (kept away from flammable materials), or by wrapping pipes with towels soaked in hot water.

What can I pour down the drain to unfreeze?

Tip #9: Hot Water and Salt Can Thaw Drainpipes

Stir a cup of kosher salt into the hot water, then pour the concoction down the frozen drain. This slurry will act like the rock salt you put down outside to melt ice-covered sidewalks.

Will pouring hot water down the drain unfreeze pipes?

Will pouring hot salt water down drain unfreeze pipes?

The job goes more quickly by pouring hot water or a mixture of vinegar, baking soda and salt water down the drain. Space heaters, hair dryers and heating pads are highly efficient tools for unfreezing a drain pipe. If a frozen drain line ruptures, turn off your home's main water supply.

What is the best way to unfreeze plumbing?

How to unfreeze pipes
  1. Turn on the faucet. Keep it running. ...
  2. Apply heat to the frozen area. Slowly apply heat using a hair dryer. ...
  3. Continue to apply heat. Don't stop heating until the full water pressure is restored. ...
  4. Check all faucets and prevent pipes from freezing in the future.

Should I turn my faucet on if my pipes are frozen?

We repeat: keep your faucets open and your water turned off while pipes thaw! Keeping the faucets open will also expedite the thawing process and allow the thawing ice to run through the pipes.

Can pipes unfreeze without bursting?

And once the temperature outside dips below 32F, unprotected pipes are at a greater risk of freezing and potentially bursting. That said, it's still possible for your pipes to thaw without bursting. The key is to release the pressure and allow the pipes to thaw slowly.

How long to run water after pipes unfreeze?

Be prepared to wait at least 30 to 60 minutes. When the pipe begins to thaw, water will start flowing at a faster rate through the open faucet. Even after the water pressure is fully restored, it's recommended to keep the heat on the pipe to ensure the ice in the line is completely melted.

Will boiling water hurt PVC pipes?

PVC drain pipes are more susceptible to damage from boiling water compared to other plastics like polyethylene and polypropylene, and of course metallic pipe materials.

Will hot water unclog a drain?

Use Boiling Water

Sometimes the simplest solutions are the most effective. Boiling water helps break down grease and soap holding the clog together to clear the blockage.

Is Drano bad for pipes?

The Short Answer Is: Drano and similar chemical drain cleaners can be harmful to home drain pipes as they contain corrosive chemicals that may deteriorate pipes over time, especially if used frequently.

What do you do if your hot water pipes are frozen?

Attempt to warm up the pipe. You can do this by applying heat to the section of the pipe using an electric heating pad, hair dryer, space heater or towels soaked in hot water. Never use a blow torch or any other open flame device when thawing pipes.

Will frozen drain pipes thaw on their own?

Frozen pipes will eventually thaw on their own, but it could take days or even weeks. If New York City is experiencing a brutal cold snap, the temperature could stay below freezing for many days. Meanwhile, the water in the pipes could be expanding.

Why do I suddenly have a water hammer?

If you've never had water hammer and one day you suddenly experience it out of the blue, then it's likely your water system's air chambers are blocked. These chambers often become blocked with water or residue from minerals found in water.

Will pouring hot water down drain unfreeze pipes?

A frozen drainpipe may usually be unfrozen by running hot water down it. Fill a half-gallon pot halfway with water and heat it on the stove. When it starts to boil, take it from the heat and pour it down the drain slowly. This may be enough to melt the ice and unclog your drain completely.

Will a frozen pipe always burst?

Although common, frozen pipes do not always burst. However, the ice can increase this risk when it thaws and is usually worsened as it raises pressure further which makes pipe bursting common near winter's end or springtime. Furthermore, the more water flowing through the pipe, the greater chance of rupture.

Why do pipes burst when it thaws?

Surprisingly, it's actually the thawing process that can cause a pipe to burst. This can happen when pressure continues to build as the newly thawed liquid begins to flow and forcefully pushes against the still-frozen areas within the pipe.

What not to do if your pipes freeze?

Don't ever try to thaw pipes with a:
  1. Blowtorch.
  2. Gas heater.
  3. Kerosene heater.
  4. Propane heater.
  5. Other open flame appliances.
  6. Any device near insulation.
  7. Electric device with extension cord.
  8. Electric heater, blow dryer, or other device near water.

Should I turn off main water if pipes are frozen?

Turn off the water immediately at the main shut off valve. Open the faucet so that water will flow through the pipe once the area is melted. This will help melt more ice.

Will frozen pipe burst if faucet is open?

It's important to note that you shouldn't fully open your faucets and plumbing fixtures directly after a freeze. This will drastically increase the water pressure within the pipes if there is any frozen water inside them, causing the pipes to burst.

How do you unfreeze pipes without bursting them?

If you have frozen pipes in your home, it can be tempting to try to heat them up as quickly as possible, but this could cause them to burst. Instead, use tools like a hairdryer, space heater, and even your home's thermostat to gradually warm the pipes.

How much does it cost for a plumber to unfreeze pipes?

As long as your frozen pipes haven't burst, a plumber will likely charge a flat fee of around $100 to thaw them out. However, the cost to repair burst pipes tends to be much higher and will ultimately depend on the extent of the damage. Expect to pay $500 on average, which includes the diagnosis and the repair itself.

How long does it take for plumbing pipes to unfreeze?

Your pipes will eventually thaw on their own, but this will take at least a few hours or potentially several days, depending on where the pipe is located and the air temperature around it.

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