Yes, in many situations it is smart to leave faucets open when the water is turned off, but it depends on why and for how long the water is off.

Should You Leave Faucets Open When Water Is Turned Off?

Quick Scoop

When the water to your home is shut off, leaving some faucets open can:

  • Relieve pressure in the pipes.
  • Help drain remaining water from the lines.
  • Reduce the risk of pipes freezing and bursting in cold weather.

But it’s not a one-size-fits-all rule. The safest move depends on whether the shutoff is for:

  • Planned repairs or maintenance
  • Freezing weather
  • A municipal outage
  • Contamination issues

When You Should Leave Faucets Open

1. During plumbing work or planned shutoff

If you or a plumber turn off the main valve for repairs, it is usually recommended to open faucets afterward. Why:

  • It relieves built-up pressure in the plumbing system.
  • It lets remaining water in the pipes drain out, which also confirms the shutoff worked.
  • Opening both hot and cold sides helps clear all lines.

Typical steps (simple version):

  1. Turn off the main water valve.
  2. Open a tub or sink faucet fully (hot and cold).
  1. Open a few other faucets around the house to help drain the lines.
  1. Leave them open while work is happening so pressure stays low.

This is especially helpful if you’re replacing fixtures, cutting into pipe, or soldering.

2. In freezing weather (to prevent bursts)

Cold climates are a special case. Freezing water expands and can build enough pressure to burst pipes. Leaving faucets slightly open can help in two ways:

  • It lets water drain or move instead of sitting pressurized in a freezing spot.
  • Even a slow trickle or open line reduces pressure buildup that leads to bursts.

Key points:

  • A slight opening or drip is generally enough; you don’t need it fully open.
  • Indoor faucets are usually safer to leave open than outdoor ones in extreme cold.
  • Draining the system and then leaving faucets open can further reduce risk in a long outage.

3. To know when water comes back (short outage)

If the city shuts off water to fix a main, some people leave one faucet slightly open so they notice when service returns.

This is usually okay if:

  • It’s a short-term outage.
  • You’re awake and nearby to shut the faucet once water flows.

However, be aware that when water comes back, there can be:

  • Bursts of air and sputtering
  • Cloudy or discolored water initially

You should close faucets and then run them briefly to flush after pressure stabilizes.

When You Should NOT Leave Faucets Open

There are situations where leaving faucets open is a bad idea.

1. Risk of flooding inside

If you won’t be home (for example, leaving for days) and you don’t know exactly when water will be restored, open faucets can become a problem:

  • When water returns, faucets left fully open can run continuously and cause indoor flooding.
  • Best practice in long absences: shut off main, drain lines, then close faucets once drained unless you have a specific freeze-protection plan.

2. Water contamination events

If water is turned off or limited because of contamination or boil-water alerts, you generally don’t want lines open:

  • Open faucets can allow contaminated water to enter and spread through the system when supply is unstable.
  • Follow local health or utility instructions in these cases.

3. Warm climates with no freeze risk

In areas where freezing is not a concern:

  • Leaving faucets open after a shutoff isn’t strictly harmful if the supply is truly off, but it’s usually unnecessary.
  • If the shutoff is temporary and you forget to close faucets, you may waste water once supply returns.

Different Scenarios (What To Do)

Below is a simple guide you can adapt.

Scenario Table

[1][5][3] [8][10][1][3] [1][5][3] [9][2] [3] [5][3]
Situation Should you leave faucets open? Reason
Planned repair, main valve off Yes, open several faucets (hot and cold) Relieves pressure and drains pipes to make work safer and reduce burst risk.
Freeze warning, water on Often yes, slight drip or partially open Moving/draining water reduces pressure buildup from freezing and helps prevent bursts.
Freeze warning, water shut off and system drained Yes, leave faucets open after draining Allows any remaining water or expanding ice to relieve pressure instead of stressing pipes.
Short city outage, you’re home Optionally one faucet slightly open Lets you see when water returns; close it promptly to avoid waste or splashing.
Long outage, you may be away when water returns Better to keep faucets closed Prevents uncontrolled flow and potential indoor flooding when service is restored.
Water shut off due to contamination No, keep faucets closed Avoids pulling contaminated water into the system and follows safety guidance.
Warm climate, no freezing risk Usually no need, maybe briefly to depressurize Leaving them open long-term offers little benefit and can waste water when it returns.

Practical Tips and Mini “Story”

Imagine you’re about to replace a bathroom faucet on a cold January morning. You shut off the main valve, then:

  1. Turn a tub faucet fully on hot and cold until the water slows and air spits out.
  2. Open a couple of sinks upstairs and downstairs.
  3. Once the flow stops, you start your work, confident the pressure is relieved and pipes are less likely to surprise you.

If temperatures are below freezing and you’re worried about your pipes overnight, you might:

  • Let an indoor faucet drip or stay slightly open, especially on problem lines (like those along exterior walls).
  • Open both hot and cold sides slightly so both lines see movement or pressure relief.

SEO-Focused Wrap-Up

  • The short answer to “should you leave faucets open when water is turned off” is: often yes for repairs or freeze protection, but no for contamination events or unsupervised long outages.
  • Check any local or utility guidance during citywide work or emergencies, as some municipalities give specific instructions.

Meta description-style summary:
When your water is turned off, leaving faucets open can relieve pressure, help drain pipes, and prevent freezing damage, but in some situations it can increase flooding or contamination risks.

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