water pressure reducing valve failure modes?

[Speedy Jim]

Yes, it is not seating and sealing perfectly, thus allowing some small flow regardless of downstream pressure. You might be able to repair it, but i think you're better off getting an identical unit and swap it in.

Jim

[John Shaeffer]

My water pressure reducing valve will control pressure under flow and can be adjusted to various settings. But when flow is shut off, pressure jumps to about 125 lbs/sq inch almost instantly regardless of pressure when there is flow. Thus this is not a water heater thermal expansion issue.

Does this mean that the pressure reducing valve needs to be replaced? Present unit is about 15 years old, Watts 25 AUB.

Thanks.

John