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How to Avoid and Thaw Frozen Pipes Safely




Every winter many people in the colder climates face the danger of frozen pipes. Naturally construction techniques should be used to minimize the possibility of frozen pipes such as not running pipes in outside walls, and through unheated areas, but, even then there is the possibility of a draft through an area that was not sealed or, insulated properly. Quite often people do things like leave a garage door open for an extended period of time, not thinking about the fact that there is a master bath above the garage with pipes in the garage ceiling and walls.

What Happens When Water In A Pipe Freezes?

When water freezes, it freezes in a hexagonal form that takes more space than in its liquid state, increasing its volume by about 9%. When a pipe freezes with two separate ice plugs the water in between the two ice plugs can generate pressures far higher than any pipe can contain, unless the pipe can stretch without breaking and accommodate this 9 % increase in volume. Water cannot be compressed and the freezing process may generate pressures as high as 40,000 PSI. When a pipe freezes fast action is necessary to prevent the freezing pipes from bursting. Almost all pipes used for water supply in the home are highly susceptible to bursting with the exception of PEX tubing. PEX is a cross linked polyethylene that has the ability to stretch without damage and contract to it’s original state when the expanding force is removed in many cases, this ability lessens the danger of PEX bursting. Other pipes such as copper, CPVC, brass, and galvanized steel cannot expand without splitting.

How To Thaw Frozen Pipes

As soon as pipe freezing is recognized by fixtures suddenly losing their water supply, immediate action is required. Hot water supplies often freeze first due to a phenomenon known as the “Mpemba effect.” Turn up the heat, leave the affected faucets open, open doors to areas such as closets, and cabinets, to allow the heat to get into the areas where the pipes are frozen. In unheated areas such as garages and crawlspaces space heaters may be used with caution. If you know the exact location of the freeze a hair dryer is a good way to warm the pipe. Warming the area of the ice plug is the only way to thaw plastic pipes. Every year many people make the mistake of using a torch to attempt to thaw pipes. Many fires are caused by this unsafe act. Do not under any circumstances use a torch to thaw frozen pipes.


Pipe Thawing Machines

If you have metal pipes such as copper, brass, or, galvanized steel you should immediately call a plumber and look for one that has an electric pipe thawing machine. If the plumber says that he doesn’t have a pipe thawing machine but can do it with his torch say no thanks. The Ridge Tool Company makes two excellent pipe thawing machines the Ridgid model KT-190 & KT-200, General Pipe Cleaners also makes 3 excellent thawing machines, the General Hot-Shot HS-320, HS-400, and the CHS-300 which is CSA Approved for use in Canada. These machines plug into a regular 120 volt receptacle and lower the voltage very low while increasing the amperage. Lowering the voltage reduces the chances of arcing virtually eliminating the danger of fire and increasing the amperage gives it the ability to produce heat when it flows through a metal pipe. These machines may thaw metal pipes up to 1 ½” in diameter without knowing the exact location of the freeze or having access to it. They will even thaw underground metal water service lines. The plumber merely has to connect the cables to the pipe on each side of the frozen section of the pipe and allow the electrical current to flow through the pipe until the ice melts. This is by far the fastest and safest way to thaw metal pipes.

Some people have attempted to use electric welders to thaw pipes. The amperage from an electric welder is certainly high enough to get the pipe warm and thaw the pipe however, unlike the pipe thawing machines electric welders provide a much higher voltage which can allow arcing to occur. Frequently when copper pipes freeze solder joints are pushed apart. If this has occurred in your home and a welder is used arcing can occur causing a fire, because of this electric welders are not recommended for thawing pipes.

How To Prevent Frozen Pipes

When you recognize that a specific area of your home has a freezing problem you should talk to the plumber about what steps can be taken to eliminate the freezing problem. Sealing the area that froze from drafts and insulating may help. Sometimes the pipes may need rerouting through safer areas. In open areas a good quality electric heat tape such as Frostex properly installed may be a good prevention measure.


What Not To Do With Frozen Pipes

One thing to avoid is the old myth of leaving the faucet running slowly to prevent the pipe from freezing. Not only is this a waste of water but it may cause a drain pipe to freeze. Frozen drains are by far the most difficult and expensive pipes to thaw. Most drains are larger than the capacity of electric pipe thawing machines and also many are constructed of materials that do not conduct electricity. The best method of thawing a frozen drain is to use a high pressure water jetter which is an expensive operation.

You should also check the plumbing fixtures in your home before the winter season to fix or, replace any dripping faucets or, leaking toilets. Drain lines should always be pitched so they drain dry when not in use. Normal use has water running through in sufficient volume and velocity that it does not cool enough to freeze while in the line. When there is a dripping faucet, leaking toilet or, other low flow into the drain there may not be sufficient volume to prevent it from freezing in your drain line. Drains that are in poor condition where they hold water in bellies or, sags are also susceptible to freezing if they are located in a cold area or above the frost line in the ground.

Above all Never Use A Torch To Thaw Frozen Pipes! You will surely get the pipes to thaw, but once the fire department leaves they will freeze again! Every year 5,580 fires in the US amounting to $208,000,000 are attributed to the use of torches, burners, and soldering equipment. Many of them involve pipe thawing operations!

Your home is no different than your car. As the cold weather approaches make sure that you home is in good shape and ready for the cold season. When problems occur, respond to them quickly and make sure that you don’t wait to call a good plumber when you run into problems such as frozen pipes.