Should I let faucets drip to prevent frozen pipes?
Yes. When it is very cold, let cold water drip from the faucets served by exposed pipes; the American Red Cross notes that running water, even at a trickle, helps keep pipes from freezing. You only need to do it for faucets fed by pipes in unheated spaces or exterior walls, not every tap in the house.
Why a drip helps
Moving water brings warmer water from the main into the cold section of pipe, which slows freezing.
It also relieves pressure. Pipes usually burst because ice blocks the line and pressure builds between the blockage and a closed faucet. An open faucet gives that pressure somewhere to go.
Which faucets, and how much
Pick the faucets at the end of pipe runs through a garage, crawlspace, attic, or exterior wall. A steady drip or pencil-lead trickle is enough.
If a faucet has separate hot and cold lines that both run through the cold space, open both slightly.
What a drip will not do
It will not save a pipe in a space that stays far below freezing for days, and it does not help while you are away with nobody to open the tap. Insulating the pipe, sealing drafts, and keeping the space above freezing are the real fixes; a temperature alert tells you when it is time to open the faucet.
Frequently asked questions
At what temperature should I start dripping faucets?
A common trigger is a forecast low around 20°F or colder, the point where research found uninsulated pipes in unheated spaces begin to freeze. Start earlier if the pipe is in a drafty spot.
Does dripping faucets waste a lot of water?
A slow drip uses little water, and you only need it on the handful of nights cold enough to threaten the pipe. That is small next to the cost of a burst pipe.
Related
- Will my pipes freeze tonight? (forecast)
- How long does it take for pipes to freeze?
- How do I thaw a frozen pipe safely?
- Cold-snap alert playbook
Sources
Get a freeze alert for your space
ProbeHarbor watches probes in garages, crawlspaces, and cabins and alerts you before pipes freeze. The free plan includes email alerts; bring an ESP32 probe or connect Home Assistant.