Water can freeze in pipes that pass through a cold location. Water expands when it freezes. Unless the pipe through which it runs also expands, it will burst. Insulation gives a pipe some protection at low temperatures but may not prevent freezing. To keep a pipe from freezing, wrap electrical heating cable around it-- one turn every 2 feet--then cover the pipe with insulation to conserve the heat. Plug in the cable when the temperatures drops below freezing. The same cable device can be used to thaw a pipe.
There are other effective thawing methods. One of the best is pouring boiling water over rags wrapped around the frozen pipe. Heating with a propane torch works quickly, but take care that steam pressure does not burst the pipe. Do not heat a pipe to a higher temperature than your hand can stand. Be very careful not to start a fire.
When thawing pipes with a heat lamp, hair dryer, household iron, or propane torch, always work from an open faucet toward the frozen area. This will keep steam from being trapped by ice and bursting the pipe. With the faucet open, you can see when the ice has melted. Do not use un-grounded electrical appliances outdoors, or near grounded water pipes.
(Vis. 1) This article was written by Anne Field, Extension Specialist, Emeritus, with references from Michigan Extension bulletin Repairing Leaky Pipes.
Thawing Frozen Pipes Pictures MSU 2003
