How to Defrost Your Pipes

Burst pipes are bad news for your home and everything it contains. Both metal and plastic water pipes may burst if you allow the water within them to freeze. When your pipes freeze, act fast and chances are you won't need to call a plumber--or your insurance agent.

Things You'll Need

• Garden Hose
• Heat Sources
• Patience

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Instructions

Thawing house water lines

1. To relieve any pressure and determine how extensive the problem is, open all faucets. If only one fixture is not working, you can assume that the pipe is frozen somewhere between that fixture and the line that leads to others. Locate where uninsulated water lines pass through an uninsulated space. Examine pipes adjacent to uninsulated foundation walls or in or adjacent to exterior walls, especially within sink and vanity cabinets, where the closed doors partially block room heat.

2. If the frozen pipe is a hot-water line, open a hot-water faucet. The moving water may thaw the pipes. If it is a cold-water line, open a cold-water faucet. If it is both or you're not sure, open both the hot and cold faucets. Keep opening faucets until the water flows freely or until you've opened them all.

3. Warm the pipes slowly wherever you have access to them. Work from an open faucet toward the frozen area. Possible approaches include hair dryers, heat lamps, towels soaked in hot water, electric heat tapes wrapped around pipes, and space heaters. If the frozen pipes extend into walls or floors, heating the pipe adjacent to where it enters and exits the wall will eventually thaw the section within the wall. Also turn up the heat in the room.

4. Let the water run for a minute or two. Then turn the faucet(s) off. Look for leaks everywhere you can see. Listen very carefully for hissing sounds where hidden pipes pass through walls or floors.

Dealing with frozen heating pipes

1. Frozen hydronic (hot-water) heating pipes present problems best addressed by a plumber. Your best bet in the meantime is to turn off the heating system's water supply, which will prevent a major flood in the event that a burst pipe thaws. Do not turn off the boiler if you have more than one heating zone on your thermostat, since another zone may be working.

2. Relieve any excess pressure in the system. Follow the same procedure you would to drain a waterlogged expansion tank: Shut the valve to the expansion tank. Attach a garden hose to the hose bib on the tank and extend the other end to a drain. Open the hose bib to drain the tank. Then close the hose bib and open the valve to the tank.

Tips & Warnings

• To limit possible flooding from a frozen pipe that may already be broken, locate the shutoff for the affected branch or shut off the water main (located where the water pipe enters the house from the street or a well).

• Once you have resolved the problem, take steps to prevent reoccurrence: Always maintain heat at no less than 55°F (13°C); open vanity and sink-cabinet doors on exceptionally cold nights; insulate pipes that pass through unheated areas, especially those adjacent to foundation walls; shut interior valves to outside hose bibs and open the outside faucet; replace standard hose bibs with freeze-proof models.

• Never use an ungrounded electrical device near metal pipes or water, or while standing on a concrete floor.

• Avoid using torches or heat guns, which create a risk of fire. Too much heat can also generate steam, which in turn can increase pressure inside the pipe and cause it to burst.