wikiHow to Prevent Frozen Water Pipes

Frozen water pipes are inconvenient and costly to repair. Here are some ways to both prevent frozen pipes and thaw those that are already frozen.


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    Insulate all water pipes from cold moving air and keep them dry. Be aware that insulation alone does not prevent freezing, it only slows down the transfer rate of heat to cold. Locate the main water shut off in case you need it. Leaks often happen if the pipe is thawed out.
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    Use either heater tapes wrapped around the pipes or a heated reflector lamp in a dry enclosed space. On cold nights, check the light to see that it is working. The heater tapes work by a built-in thermostat. In order to work, the tape must be wrapped between the pipe and the insulation. Some tapes do not allow insulation over heat tape. Follow manufacturer instruction.
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    If electric power is unavailable or is lost, let the water run no faster than a slow constant drip; this is cheaper than repairing it. First start a slow drip on the hot side faucet, then a faster drip on the cold side faucet. There is no need to run a lot of water. Bathrooms can be cold, as long as they aren't freezing.
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    Remember to insulate and heat the drain lines in crawl spaces and cold basements. Again, a heat lamp focused on the drain p-trap will keep it from freezing if it is also protected from moving cold air with a boxed enclosure that you can build yourself.
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    To thaw a frozen pipe, first check the pipe in the area of the freeze. Some plastic or copper pipes will split and will flood the area when thawed. If the pipe looks busted or has a slit in it, call a plumber. If the pipe is all metal, it can be thawed by connecting a welder onto the pipe on each side of the frozen part. The practice of using a welder is not recommended unless you know what you are doing. You should set up a fuse between the welder connection and the frozen pipe. The welder must be the correct type and must be set at a low voltage, and must be turned off at the appropriate time so you do not overheat and melt your solder joints. Read your welder operation manual to see if your arc welder can be used for melting frozen pipes. Be aware that pipes with low resistance will easily create more heat in the welder machine than in the pipes.
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    It is far better to heat the area around the frozen part with an electric space heater, a hand-held hair dryer, or a heat lamp in a reflector to prevent a fire. Use care when placing heat generating devices. Space heaters, heat lamps and reflective lamps can generate high temperatures which may cause combustion of certain materials, Never leave these devices unattended for any amount of time when in use. If this is a problem, call the plumber. Some of them don't mind if you watch them as long as you are quiet and not in the way.
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    Always disconnect your water hose from your outdoor spigot in the winter, or before the temperature in your area drops below freezing. The water inside the hose can freeze, and the freezing continues back into the spigot until it reaches your pipes. Any pipe that freezes can burst.
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    Use a temperature-controlled thermal convection powered hot water recirculation valve (which does not require electricity to operate) to continuously circulate warm water throughout your hot and cold waterlines anytime the temperature is below the user chosen set point 77F-140F. Unlike heat tape which only heats the pipes, this process circulates water non-stop to prevent crystallization and freezing no matter where the pipes are hidden. Note: This method requires that the valve be installed at a higher level (2nd - 3rd floor) than the water heater. Circulating water throughout your system "non-stop" will also increase your water heating bill. Anytime circulation,is not desired uninstall the valve.
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    Use a product called ICE LOC which prevents pipes from rupturing by taking up the expansion of the frozen water. It's an elastomer that fits inside pipes that are in trouble areas.
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    Use a RedyTemp, a device which utilizes an internal water contacting temperature probe to monitor the temperature of the water inside the pipes. Depending on the temperature set point you choose on the unit's temperature dial, it will intermittently circulate water throughout both hot and cold water lines "as needed" to maintain the selected temperature. Intermittent circulation typically results in 5 minutes of actual circulation per hour causing far less water heater demand compared to continuous demand from thermostatic valves. The RedyTemp optimizer installation is a DIY project and takes twenty minutes to install under a sink. Disconnect one end of the existing faucet supply lines and connect to the RedyTemp. Connect the two faucet supply lines which come with the RedyTemp. Plug the unit into a standard wall socket and set the desired temperature set point. Users can gauge the effectiveness of their chosen set point by opening cold water faucets upstream and feeling how cool/ambient/warm the water is coming out the tap, and adjust the set point accordingly until optimized. An optimized set point is achieved when cool or ambient temperature water is maintained in the cold water pipes or the portion of pipe requiring protection. RedyTemp's low 40 watt / 0.52 amp intermittent power consumption allows using a uninterruptible power supply for continuous protection during power outages. Owners of tankless on-demand water heaters require RedyTemp TL4000 series model rather than the ATC3000 depicted in the illustration. During off seasons when circulation is not desired users simply lower the temperature set point to prevent circulation.


  • If you hire somebody to do this, ask questions and expect answers. You are paying them money.
  • Consider hiring a licensed plumber if you have any reservations about following the steps in this article.
  • If they say they won't guarantee their work, ask them who does, and call them. Refuse to pay if the work is not performed correctly.


  • If this sounds like too much, get help. Better safe than sorry.
  • Do NOT use any kind of open flames, it may burst your pipes.

Things You'll Need

  • Enclosure
    • Plywood and 2x4's cut to size to cover the problem area
    • Plasterboard screws
    • Portable electric screwdriver
    • A drop light
    • Make the enclosure box to fit between the bottom of house and ground in a crawl space. Be sure to make it air-tight and insulated. Make a cover on one side that removes easily.
  • To prevent freezing
    • Pipe insulation
    • Heat tape
    • Reflector heat lamp
  • To thaw frozen pipes
    • Hand-held hair dryer or reflector heat lamp

Article Info

Categories: Plumbing Drains Waste and Vents