Low Water Pressure? Here's What to Check

Low water pressure makes showers miserable and fills a pot painfully slowly. The fix depends on whether it's one fixture, one room, or the whole house. Start by narrowing it down — the most common cause is a clogged aerator, which takes 2 minutes to fix.

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Key takeaway: Low pressure at a single faucet is usually a clogged aerator — a 2-minute fix. Whole-house low pressure points to a partially closed valve, failing pressure regulator, or a hidden leak.

What's Happening

Water pressure drops when something restricts the flow between the water main and your fixture. Common culprits include clogged aerators (the screen on your faucet tip), partially closed shutoff valves, mineral buildup in pipes, a failing pressure regulator, or a leak somewhere in the system. Municipal supply issues can also cause temporary low pressure.

What to Check

Determine the scope. Test every faucet and shower in the house, both hot and cold. If only one fixture is affected, the problem is local. If only hot water is weak, the water heater or its valves are the issue. If the whole house is affected, it's a supply-side problem.
Clean the aerator (single fixture). Unscrew the aerator from the faucet tip by hand or with pliers (wrap the jaws in tape to avoid scratches). Disassemble it, soak the screen in white vinegar for 30 minutes, scrub with an old toothbrush, and reinstall. This fixes the issue about 40% of the time.
Clean the showerhead. Unscrew the showerhead or tie a bag of vinegar around it so the head is submerged. Soak for 2-4 hours or overnight. Scrub any remaining deposits. Reinstall.
Check shutoff valves. Find the main shutoff valve (usually near the water meter or where the main line enters your house) and any local fixture shutoff valves. Make sure they're fully open — even a quarter turn closed can reduce pressure significantly.
Check for leaks. Turn off all water in the house. Read your water meter, wait 2 hours without using any water, and read it again. If the meter moved, you have a leak somewhere.

DIY Cost

$0–10

Pro Cost

$150–500

⚠ Call a Pro If

Pressure dropped suddenly throughout the entire house
Your water meter shows water flowing when everything is off (hidden leak)
You have galvanized steel pipes (common in pre-1970s homes) — they corrode internally
Cleaning aerators and checking valves didn't help

Frequently Asked Questions

Why is my water pressure suddenly low?

Sudden drops can be caused by a partially closed shutoff valve, a water main break, a leaking pipe, or a failing pressure regulator. Check valves first, then call your water company.

How do I check my home's water pressure?

Attach a pressure gauge ($10) to an outdoor hose bib. Normal is 40-60 PSI. Below 30 is low; above 80 is too high.

Can low water pressure damage appliances?

Very low pressure can prevent washers and dishwashers from filling properly. It won't damage them but affects performance.

Not Sure Where the Pressure Drop Is Coming From?

Record a video showing where pressure is low and Toolbox narrows down whether it's a fixture, zone, or whole-house issue — so you're not guessing at a fix.

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