Why Is My Water Pressure Suddenly Low?

A sudden pressure drop can have a very simple cause, or it can be the first sign that something changed in the plumbing system. Where the problem shows up is your best clue.

Is it one fixture or the whole house?

Turn on a few fixtures and check both hot and cold. One weak faucet while everything else runs normally means you start at that fixture. Low pressure everywhere means the cause is probably farther upstream.

One faucet has low pressure

A faucet aerator can collect mineral buildup or debris. A showerhead can do the same. Clean the accessible parts according to the manufacturer's directions before assuming there's a bigger problem in the plumbing.

What if only the hot water is weak?

Cold pressure normal but hot pressure poor at several fixtures points to the water-heating side of the system. That's a different problem from a whole-house pressure drop.

What if the entire house has low pressure?

First check whether the main water valve has been left partially closed. If the home has a pressure regulator, a regulator problem can also affect everything at once. Don't adjust a regulator at random, though. Pressure set too high creates plumbing problems of its own.

Could there be a leak?

Possibly. A sudden, unexplained pressure loss sometimes accompanies a significant leak. Look for new wet spots, sounds of running water, unexpected meter movement, water stains, or moisture around the property.

Could it be the water utility?

It can be. Utility work or a neighborhood supply problem can lower pressure temporarily. If the neighbors are experiencing the same thing, the cause probably isn't inside your house.

When should I get help?

Consider professional evaluation when:

• Pressure dropped suddenly throughout the house.
• You suspect a hidden leak.
• The main valve is damaged.
• Pressure stays low after simple fixture checks.
• The problem keeps getting worse.

If you've checked the obvious causes and pressure remains low throughout the house, the problem may be farther upstream in the plumbing. That's a reasonable point to have the pressure and supply lines evaluated. Find Local Plumbing Help