The Truth About Dripping Faucets, Frozen Pipes And Extreme Cold

Much of the United States is bracing for dangerously cold temperatures this weekend. Now is the time to prepare for this Arctic intrusion because it is life-threatening. Here in the Atlanta area, wind chill values will approach 0 degrees F. Values in the Midwest are even more scary (map below). As my wife and I traveled home from the mall today, we were reflecting on the old-school advice to “leave the faucets dripping when it gets really cold to prevent pipes from freezing or bursting.” While there is truth to it, there are others that do not recommend this strategy. Let’s explore it more carefully.

The City of Houston, Texas warns its residents not to do it because it can cause the water system across the city to lose pressure. In 2021, a spokesperson for the city told KHOU 11 that such consequences could hinder firefighting efforts or lead to boil water advisories. Yet, many jurisdictions or organizations recommend the practice. On the GEICO website, Jeff Bell of Mr. Rooter Plumbing of Southern Massachusetts, recommends leaving a solid, cold trickle running during extended cold weather to prevent pipe freezing.

There is mixed information on this practice internationally as well. In 2018, Richard Burke of the Heating and Plumbing Association of Ireland told the TheJournal.ie that leaving water running is just a myth. He even went on to say that it can cause freezing of the drain as it flows out of the sink. He also reminded readers that there is not much that can be done about water main pipes coming into the homes that freeze.

So what are we supposed to do? The scientist in me knows that pipes likely burst because of the increased pressure caused by ice in the pipes. Some experts argue that the dripping faucet prevents excessive pressure build-up. Plumbing organizations estimate that freezing water can exert on the order of 10,000 to 100,000 psi on a pipe. The Legacy Plumbing website notes, “The principle behind leaving faucets dripping is that it constantly replaces the cold, near-freezing water in the most vulnerable pipes with fresh, warm water from the pipes below the ground.” However, they have a slightly different recommendation. Their site goes on to say, “The pipes that come up in the interior walls are already kept warm by the heat of your house’s furnace. It is the pipes that run through the vulnerable exterior walls that you want to protect.” They recommend focusing your “drip” strategy on faucets on the exterior walls.

On its website, Top of the Line Plumbing recommends that you keep the home adequately heated, leave cabinets housing pipes open, and insulate vulnerable pipes especially in places like basements, attics, or exterior walls. The National Rural Water Association (NRWA) has a similar set of recommendations below.