How to Thaw a Frozen Water Line

What You'll Need
High power hair dryer
Hot water
Portable heater
Cookie sheet (optional)

Freezing winter temperatures can cause a frozen water line in your home. When exposed to extreme temperatures, uninsulated pipes can freeze. Water expands as it freezes and can cause a frozen water line to rupture from the pressure, requiring costly pipe replacement and water damage repairs. If your water lines freeze, immediate action is required to thaw them before they burst.

Step 1 - Locate Frozen Water Line

Before you can thaw a frozen water line, you must first locate it. Fully open all the faucets in your home. If all but one of the faucets is running properly, you know the problem is located in the water line supplying that faucet. Close the unaffected faucets, but leave the frozen line open so the pressure can be released as it is thawed.

If none of the faucets are running, the problem lies with the main water line coming into the house, located at the meter. Leave all faucets open to release pressure from thawing the frozen line.

Step 2 - Thaw Main Water Line

Use a high power hair dryer to thaw a main water line. Start from the top of the pipe nearest the faucets and work your way back to the meter. Continue to use use the hair dryer until the pipe is thawed and water runs freely through all faucets.

Step 3 - Thaw Exposed Water Line

If one faucet is not running, you must locate the frozen area of the line. Work your way back from the faucet, checking for exposed areas that feel colder than others or show visible frost. If the pipe is plastic, soak towels in hot water and wrap them around the pipe. Reheat the towels in hot water when they become cold. Continue until the pipe is thawed and water runs freely.

For frozen metal pipes, use a high power hair dryer to thaw the frozen area more effectively. Work backward from the faucet to allow drainage as the ice melts. For an exposed water line that is close to a wall, place a cookie sheet behind the pipe and use the hair dryer, The cookie sheet will reflect heat back to the pipe, allowing it to thaw more quickly. Continue to heat the pipe with the hair dryer until water runs freely.

Step 4 - Thaw Unexposed Water Line

Sometimes the frozen water line will be behind a wall and inaccessible to you. If that is the case, turn up the heat in your home and open all cabinet doors to allow heat to radiate. Place a portable heater no less than 18 inches from the wall where the frozen water line is located. Use the hair dryer on any exposed water line leading to and from the frozen pipe, starting with the area closest to the faucet. This method will take longer, but will prevent having to tear out a wall and replace it.