If you turn on the faucet and only a trickle flows out, you may have a frozen pipe. “If you suspect the pipes are frozen, be careful when thawing them, because if the pipe has already burst, the water will flow out and flood your home,” says John Galeotafiore, who oversees Consumer Reports' testing of home products and electricity Corridor.
If a pipe is broken, turn off the water at the main shutoff valve, usually located at the water meter or where the main line enters the house. If the water is still running and no pipes have burst, you can take the following steps. (Of course, if you suspect a more serious problem, contact a plumber.)
Turn on the faucet. As you heat the frozen pipe and the ice plug begins to melt, you want the water to be able to flow through it. Running water through the pipe, cold as it is, helps melt the ice in the pipe.
Warm the pipe section using an electric heating pad wrapped around the pipe, an electric hair dryer, or a portable space heater (keep away from flammable materials), or by wrapping the pipes with towels soaked in hot water. As tempting as it may be, do not use a blowtorch, kerosene or propane heater, charcoal stove, or other device with an open flame. The high heat can damage the pipes or even cause a fire.
Apply heat until full water pressure is restored. Check all other faucets in your home to see if any other pipes are frozen. If one pipe freezes, others may freeze too.
Call a licensed plumber if you cannot find the frozen area, if the frozen area is inaccessible, or if you cannot thaw the pipe.