Low Water Pressure Throughout the House
Low pressure throughout the whole house is different from low pressure at one faucet. Whole-house low pressure typically points to the pressure reducing valve (PRV), the main shutoff, or the water supplier. Single-fixture low pressure is usually a clogged aerator or faucet cartridge.
Step-by-Step Fix
- 1
Test if it's whole-house or one fixture
Check multiple faucets on different floors. If only one faucet has low pressure, clean its aerator (the screen at the tip), unscrew it and soak it in vinegar for 30 minutes. If multiple fixtures are low, continue below.
- 2
Check the main shutoff valve
Find the main water shutoff valve (usually near the water meter, at the front of the house). Make sure it's fully open, a gate valve should be turned fully counterclockwise, a ball valve should be parallel to the pipe.
- 3
Check the pressure reducing valve (PRV)
Most homes have a PRV, a bell-shaped device on the main supply pipe. Normal home pressure is 45–80 PSI. Attach a pressure gauge to an outdoor hose bib to test. If pressure is under 45 PSI, try turning the PRV adjustment screw clockwise a quarter turn and retesting.
- 4
Look for a shutoff that's partially closed
If you recently had any work done, check that all service valves under sinks and behind toilets are fully open.
- 5
Check with a neighbor
If your neighbor also has low pressure, contact your water utility, it may be a supply issue on the main line, not something you can fix.
⚠️ Safety Notes
- Don't raise PRV pressure above 80 PSI, this stresses pipes and can cause leaks and damage to appliances.
- A PRV that's completely failed needs to be replaced, this requires shutting off water at the street and is best done by a plumber.
When to Call a Pro
If adjusting the PRV doesn't restore pressure, or if the PRV is leaking, have a plumber replace it. Also call if you have galvanized pipes (common in homes built before 1970), they corrode internally and may need replacement.
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