Quick answer
When water pressure drops in every fixture at once, start outside the house. Ask neighbors or the water utility whether there is a main break or work in the area. Then check that the main shutoff and the meter valve are fully open, especially after any recent plumbing work. If the home has a pressure-reducing valve near the main, a failing one can drop pressure suddenly. A hidden leak in the service line or under the slab also lowers pressure; watch the meter with all water off. Call (888) 217-6781 to reach a plumbing company taking calls in your ZIP.
Follow the short menu, then your 5-digit ZIP. The line goes quiet for a few seconds while it connects; stay on. If it does not connect, call once more: companies taking calls change minute to minute.
Written & reviewed by Marcus ReedIICRC WRT
Reviewed November 4, 2026· Next review May 2027
Pressure that drops in one faucet is a fixture problem. Pressure that drops everywhere, all at once, means something changed in the supply to the whole house.
Check in This Order
- 1The utility. Ask a neighbor whether their pressure dropped too, or check the water utility's outage page. Main breaks, hydrant flushing and repairs lower pressure for everyone nearby.
- 2The main valve. Make sure the main shutoff inside, and the valve at the meter, are fully open. They are often left partly closed after plumbing work.
- 3The pressure-reducing valve. Many homes have a bell-shaped regulator just after the main. When it fails, pressure can drop suddenly. See signs of a bad pressure-reducing valve.
- 4A leak. Turn off every fixture and watch the meter. If the dial or leak indicator moves, water is escaping between the meter and the fixtures. See main water line leak.
- 5A gauge. A pressure gauge on an outdoor hose bib gives a number to compare with the regulator's setting.
What It Points To
| What you find | Likely cause |
|---|---|
| Neighbors affected too | Utility issue |
| Valve was partly closed | Fixed when opened fully |
| Gauge low, regulator adjustment does nothing | Failing regulator |
| Meter moves with everything off | Leak in the service line or slab |
| Only hot water is weak | Water heater valve or sediment |
Talk to a plumber about this
One call reaches a plumbing company taking calls in your ZIP.
When It Is a Leak
A leak strong enough to lower pressure is losing a lot of water. If you hear running water with everything off, or see wet ground over the service line, close the main and call.
The Call
Call when the utility is fine, the valves are open, and pressure is still low. (888) 217-6781 connects you to a plumbing company taking calls in your ZIP. Follow the short menu, enter your 5-digit ZIP and stay on while it connects; if it does not connect, call once more, because the companies taking calls change minute to minute.
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Frequently Asked Questions
Why did my water pressure suddenly drop in the whole house?
Utility work or a main break, a main valve left partly closed, a failing pressure-reducing valve, or a leak in the service line or under the slab.
How do I know if my pressure regulator is bad?
Pressure drops or swings, a gauge on a hose bib reads well below its setting, or adjusting the screw changes nothing.
Can a leak cause low water pressure?
YesA leak in the line from the meter or under the slab diverts water and lowers pressure at the fixtures. The meter moving with all water off confirms it.
Sources
Methodology: How we source and verify data · Report an error
Disclaimer: HearthDry is an independent educational resource. This article is for informational purposes only and does not constitute professional, legal, or insurance advice. Consult licensed professionals before making decisions about your property or insurance claims.
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