What the PRV does
Water in the city main can arrive at a higher pressure than household plumbing is designed for. A pressure-reducing valve, often a bell-shaped brass valve near where the line enters the house, steps that pressure down to a steady level for everything downstream.
Like any valve with a spring and diaphragm, a PRV wears. Mineral buildup from hard water can make it stick, and over time it may let more and more pressure through. Because the change is gradual, many homeowners only notice when fixtures start to drip, toilets refill on their own or pipes begin to bang.
Signs pressure may be too high
Testing your own pressure
A simple screw-on gauge from a hardware store gives a useful first reading.
Pick a hose bib
Use one near the main line, ideally on the house side of the PRV.
Turn off water use
Make sure no faucets, irrigation or appliances are running.
Read static pressure
Screw the gauge on, open the bib fully and note the reading.
Check over time
Some gauges have a tell-tale needle. Leave it overnight to see whether pressure climbs when no one is using water.
Write it down
Bring the readings to a plumber. A reading that climbs overnight can point to thermal expansion as well as the PRV.
Reading the results
- Ifthe reading is steady and within the range a plumber considers normalthe PRV is likely working; look elsewhere for the symptom.
- Ifthe reading is high right awaythe PRV may be failing or need adjustment; have it checked.
- Ifpressure starts normal and climbs overnightask about thermal expansion and whether an expansion tank is needed or has failed.
- Ifyou cannot find a PRV at allask a plumber whether your home has one and whether it should.
Adjust, rebuild or replace
Adjust or rebuild
- May work when the valve is in good shape but set high
- Some valves accept rebuild kits
- Less disruption to piping
Replace the valve
- Usual answer when the valve body is worn or seized
- Requires shutting off water at the street side
- Gives a known-good starting point
Questions to ask the plumber
- What pressure did you measure, and what are you setting it to?
- Is the valve adjustable, rebuildable or due for replacement?
- Should I also have thermal expansion control at the water heater?
- Did high pressure damage any fixtures or the relief valve?
Common questions
Is high pressure dangerous?
It mostly shortens the life of fixtures, valves, appliances and joints. Over time that can lead to leaks, so it is worth correcting.
Can I adjust the PRV myself?
Many have an adjustment screw, but turning a worn valve can make things worse. Measure first and let a licensed plumber adjust or replace it.
Does the city control my house pressure?
The city water utility controls pressure in its mains. Pressure inside your home after the meter is managed by your own regulator.
General information for Amerige Heights, not a quote or professional advice. In an emergency, call 911.