Symptoms
- Water pressure suddenly much higher or lower than normal
- Banging pipes that started around the same time as a pressure change
- Fluctuating pressure throughout the day
- Visible leaking or corrosion at the regulator itself
Likely causes
- CommonInternal spring or diaphragm wearing out with agePRVs typically last 10–15 years before internal components degrade and stop regulating properly.
- CommonMineral debris lodged in the valve mechanismSediment can prevent the valve from adjusting properly, causing pressure to run high or low.
- PossibleValve set incorrectly (adjustable models)Some PRVs have an adjustment screw that may have been bumped or improperly set during past work.
- Less commonCorrosion or physical damage to the valve bodyAge and water quality can corrode the valve body itself, beyond just internal wear.
What to do
- Attach a water pressure gauge to an outdoor spigot or a laundry connection to get an accurate current reading.
- Compare the reading to a normal range of 40–60 psi; readings well above 80 psi or below 40 psi suggest the regulator isn't working correctly.
- Locate the PRV, usually near where the main water line enters the house, often a bell-shaped valve with an adjustment screw on top.
- If accessible and adjustable, a small turn of the adjustment screw (clockwise to increase, counterclockwise to decrease) can sometimes correct minor deviations.
- Avoid major adjustments without confirming you're turning the correct direction for your specific valve model.
- If pressure doesn't stabilize with adjustment, or the valve shows visible corrosion or leaking, it likely needs replacement.
- Have a plumber replace the PRV if adjustment doesn't help, since incorrect installation can cause pressure problems or damage to fixtures.
Tools and parts
- Water pressure gauge
- Wrench (for adjustment screw)
Pressure-reducing valve replacementSearch: “water pressure reducing valve”
When to call a pro
Call a plumber to replace a failing PRV, since improper installation can affect pressure throughout the entire house.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.