Common Causes of Low Water Pressure
Low pressure at one faucet points to a different cause than low pressure throughout the house.
The cause of low water pressure depends a lot on where it's happening. Narrowing that down first — one fixture versus the whole house — makes it much easier to identify the actual problem.
Low Pressure at a Single Fixture
Mineral deposits inside the faucet aerator or showerhead are the most common cause, especially in areas with harder water. Removing and cleaning the aerator is a simple first step before assuming a bigger issue.
Low Pressure Throughout the House
This usually points to something upstream — a main shutoff valve that isn't fully open, a pressure regulator that's failing, or, in older homes, corroded pipe that's gradually narrowing the space water can flow through.
Sudden Drops in Pressure
A pressure drop that happens suddenly, rather than gradually, is more likely to indicate a leak somewhere in the system pulling water away from the rest of the house.