Why Is My Water Pressure So Low?
Low water pressure is one of those quality-of-life problems that starts as a minor annoyance and eventually gets really frustrating. Weak shower spray, a faucet that takes forever to fill a pot — there’s usually a fixable cause. Here’s how to work through it.
First, Figure Out the Scope
Is the low pressure everywhere in the house, or just at one fixture? If it’s just one faucet, the problem is almost certainly local — a clogged aerator or a partially closed valve under the sink. Unscrew the aerator (the small mesh screen at the tip of the faucet), rinse it out, and reinstall it. That alone fixes the issue in a large percentage of cases.
Check the Main Shutoff Valve
If pressure is low throughout the house, check that your main shutoff valve is fully open. It’s usually near where the water line enters the house. A valve that’s only three-quarters open can significantly reduce pressure everywhere.
Pressure Regulator
Many homes have a pressure reducing valve (PRV) on the main line. These wear out over time — typically after 10–15 years. A failing PRV can cause pressure to drop house-wide. A plumber can test it and replace it if needed; the part usually runs $50–$100 and replacement is a couple hours of labor.
Mineral Buildup in Pipes
In older homes with galvanized steel pipes, mineral deposits build up inside the pipe walls over decades, restricting flow. If your house is 40+ years old and has never had the plumbing updated, this could be the root cause. It’s not a quick fix — repipe jobs are significant projects — but knowing the cause helps you plan.
Call the Water Company First
Before you do anything, call your municipal water supplier and ask if there are any pressure issues in your area. Sometimes it’s not your house at all — it’s a main-line issue down the street that they’re already working on.