Outside temperatures plummet. Your house feels warm and comfortable. You turn the faucet for water and nothing comes out. The cold has penetrated enough to freeze your water pipes. The clock may be ticking for how long you can let the pipes be frozen before the ice causes them to burst. It is time to make thawing these pipes a high priority.
Do not be in a hurry.
It is important to keep working on the problem, but undue haste can result in making the problem worse. Search until you locate the most likely place that the pipe is frozen. Now, you need to find a way to increase the temperature surrounding the pipes until the water thaws enough to run again.
Keep in mind that you do not want to create pressure in the lines.
Heating the line too quickly can create new problems. As the ice melts, it reduces in size, but as the water heats up, it increases in size. The problem that can develop is that you heat the water too much near the ice plug and cause a pressure build up that can rupture the pipe. Slow warming helps melt the ice without overheating the water.
You need to have direct access to the water pipes in most cases.
This may require you to open up a wall or crawl under the house. It is best if you can get your heat source right next to the frozen water pipes. In some cases you might have to dig down into the ground to get near enough to thaw the pipes.
Pay attention to the possibility of fire hazard if you use a flame.
You have choices when it comes to the source of heat you use to melt the ice. For lines under a house or in a wall, you may want to use something like a hair dryer or electric heat gun. Almost any type of heat will work. If you have metal pipes, you may be tempted to use a torch. If the pipes are outside of the house in the ground, a fire built over the blocked pipes can warm the ground enough to thaw them. Just think safety first. You do not want to burn your house down or get electrocuted.
Open a faucet.
Before you start to thaw the pipes, turn a faucet on that is connected to that water pipe. This will do two things for you. First, it will help relieve pressure that might build in the line as the water heats up. Also, this will let you know when the blockage is starting to thaw because the water will start to flow from the faucet.
Stop applying outside heat once the water starts to run.
Running water will thaw any remaining ice in the water pipes. Let the water flow until the stream is back to normal pressure. If the weather is remaining cold, you will want to let the water run at a trickle until the weather improves. This will prevent the line from refreezing. You may also want to wrap the water pipes with insulation or heated tape to keep them thawed.