When temperatures drop below freezing, you generally want to drip the faucets that are most at risk of feeding frozen pipes, not every single tap in your home.

Key idea: keep vulnerable pipes moving

The whole point of dripping faucets is to keep water moving through pipes that might freeze and burst in very cold weather. Moving water is harder to freeze than standing water, and even a tiny trickle can be enough to prevent ice from forming inside pipes.

Which faucets to drip

In a typical freeze event, prioritize:

  • Faucets served by pipes that run through unheated or poorly insulated spaces (garages, attics, crawl spaces, exterior walls, basements).
  • The faucet farthest from your water meter or main shutoff valve, so that water is moving through the longest, most vulnerable stretch of pipe.
  • Inside faucets on exterior walls, especially in kitchens or bathrooms where the sink backs up to the outside of the house.
  • Both hot and cold sides on at least one faucet if those lines are separate, so that both hot- and cold-water pipes see some flow.
  • Outdoor faucets, but only if they can’t be fully shut off and drained; otherwise they’re normally winterized instead of left dripping.

A good rule of thumb: if a pipe would feel “close to the outdoors” (thin wall, drafty area, unheated room), it’s a candidate for a dripping faucet on that line.

When to drip

  • Start dripping when outdoor temperatures are expected to stay below about 20°F (around –6°C) for several hours, especially overnight.
  • Keep the drip going until temperatures are safely above freezing again and no longer dipping below 32°F.

How much to drip

  • You don’t need a stream—just a slight trickle or a drip every few seconds is typically enough to keep water moving and reduce freeze risk.
  • In extreme cold (approaching 0°F or below), you can open the faucet a bit more than a drip to be safer.

One quick example

Imagine a one-story house with:

  • A kitchen sink on an exterior wall,
  • A bathroom in the middle of the house,
  • Laundry in an unheated garage.

On a very cold night, you’d drip:

  • The kitchen sink (exterior wall),
  • The laundry faucet in the garage (unheated),
  • And choose whichever of these is farthest from the meter to ensure the longest pipe run is protected.

Information gathered from public forums or data available on the internet and portrayed here.