Call a Plumber Soon Avg. cost: $200
Low Water Pressure: Causes, Fixes & When to Call a Plumber
Low water pressure is caused by clogged aerators, partially closed shutoff valves, pipe scale buildup, pressure regulator failure, or main line leaks. Clean aerators first; if multiple fixtures are affected, call a plumber to diagnose the source.
What Causes Low Water Pressure?
- Clogged faucet aerator or showerhead
- Partially closed shutoff valve at the meter or home
- Pressure reducing valve (PRV) failure
- Pipe corrosion or scale buildup narrowing flow
- Leak in the main supply line losing pressure
- Municipal supply pressure drops
How to Fix Low Water Pressure: Step-by-Step
- 1Unscrew and clean faucet aerators — soak in white vinegar for 30 minutes
- 2Verify main shutoff valve is fully open
- 3Check if pressure is low on both hot and cold (cold only = supply issue; hot only = water heater issue)
- 4Test pressure at an outdoor hose bib with a pressure gauge ($10 at hardware stores); normal is 40–80 PSI
- 5Clean showerhead by soaking in vinegar overnight
When Should You Call a Plumber?
Call a plumber if pressure is low throughout the house, below 40 PSI, you find a wet patch in the yard (main line leak), or cleaning aerators doesn't help.
How Much Does Low Water Pressure Repair Cost?
Average Cost $200
Typical Range $100 – $800
Costs vary by location, severity, and whether emergency service is needed. Prices shown are national averages. Get a free quote from a local plumber →
Frequently Asked Questions About Low Water Pressure
- Ideal water pressure is 40–60 PSI. Above 80 PSI stresses pipes and appliances. Below 40 PSI makes showers weak and appliances slow. A pressure gauge test takes 30 seconds and costs about $10 at any hardware store.
- Sudden pressure drops typically indicate a main line leak, a shutoff valve was partially closed, or your municipality has a supply issue. Check with neighbors — if they have the same problem, it's a utility issue.
- Yes — PRVs are set to regulate pressure entering your home. They can fail in the closed position, causing very low pressure throughout the house. A plumber can test and replace a faulty PRV in 1–2 hours.