How to Thaw Frozen PEX Water Lines

PEX water lines
  • 1-3 hours
  • Beginner
  • 0-50
What You'll Need
Hot water
Length of rubber tubing
Blow dryer

PEX water lines are a thermo set material that is cross linked. Despite the fact that PEX piping is made from a high density polyethylene and is popular specifically because of its ability to withstand intense hot or cold. However, in extremely cold temperatures these lines can still freeze up. While this is something that is not common, it is still possible. If your piping is frozen, there is a simple DIY solution to your problems.

Step 1 - Check for Cracks

First, make sure that none of the water lines have cracked. Sometimes, the water will expand whenever it is frozen into ice and the eventual force of the ice expanding in the water line can easily cause it to crack.

If there is a crack, then you will need to repair the entire water pipe, but otherwise continue with the thawing process.

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Step 2 - Turn off Water

Once you have checked to make sure that your frozen PEX water line has not in fact split, you are ready to turn off the water that is leading into the line. If you are in an older home, then you will usually have to shut off your main water supply that goes directly into your home.

However, if you happen to have a new home, then you will be able to find intermediate water shut off valves that may be installed. This will allow you to simply isolate the frozen water line that you are going to have to work on.

Step 3 - Open Faucets

Once the water has been turned off, you will need to open up any faucets that the frozen water line connects to. This will allow you to completely get rid of the cold water that is inside of your pipe and lowers pressure so that the water can flow out of your pipe easily, once it’s been completely thawed.

Step 4 - Thaw

You are now ready to thaw your water lines. There are a couple of different ways that you can go about doing this. It will depend on what you already have available as well as how hard it will be to get to your PEX water line that is frozen. The PEX piping that froze up can be heated using either a blow dryer to create a point of heat for the ice and water to travel through. Alternatively, you can wrap the PEX line cloths or bath towels and pour out hot water from your kettle over the towels. If you can’t access many parts of the piping, just focus repeatedly on the lengths you can interact with. Heating those small spots considerably and consistently should eventually promote the thawing of the ice.

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