With the extremely cold weather, consider leaving a faucet running at a trickle, especially for pipes exposed to the cold. Moving water is less likely to freeze. If you have had a water service pipe that has frozen in the past, this is especially important. A slightly higher water bill is better than a costly frozen service line. Note that most water service lines are installed below the normal frost line and are not subject to freezing during a normal cold winter. Pipes in crawl spaces are especially vulnerable during extreme cold weather.