When freezing temperatures outside result in your plumbing suddenly losing water pressure, you need to take action to find the source and fix the problem. If you cannot determine exactly what pipes are causing the lower water pressure or if you have trouble accessing the pipes, it's time to call a plumber.
When the water in the plumbing's supply pipes partially freezes, the frozen water essentially creates a partial blockage in the pipes. The partial blockage lowers the water pressure because less water can pass through the pipe. Pipes can freeze when the outside temperature is 20 degrees Fahrenheit or less, according to Texas A&M University. Pipes located in uninsulated parts of the house such as the garage or basement, as well as those that sit against an exterior wall with little insulation, are more likely to freeze in the cold weather.
If the water in your pipes freezes, the expanding water can cause damage to the pipe. The pipe might even spring a leak, which can cause a drop in the water pressure inside your home. If you have several leaks, that can cause an even greater drop in pressure.
Preventing Freezing Pipes
Taking steps to keep your water supply lines from freezing can help eliminate problems with low water pressure before they occur. If your outdoor faucets are not frost-free, close the shutoff valves and drain any leftover water from the faucets before the cold weather hits. Insulate pipes that do not have insulation, using a sleeve insulation kit or fiberglass insulation. Avoid leaving the garage door open for longer than necessary during the winter, since the decreased temperature in the garage may cause pipes in the garage to freeze. If you are still afraid specific pipes may freeze, let water drip from the faucets connected to the pipes. To protect against frozen pipes, never set your house's thermostat below 55 degrees Fahrenheit when the outside temperatures are at or below freezing, according to the American Red Cross.
When you realize that your water supply pipes have frozen, you need to thaw the water in the pipes to restore the water pressure. First, open the faucet connected to the frozen water supply pipes so the water can start flowing through the pipe once the ice begins thawing. You can use a space heater to heat the area where a pipe has frozen, or apply heat directly to the frozen pipes with a hair dryer or by wrapping towels soaked in hot water around the pipes. Using an open flame on the frozen pipes may cause them to burst.