A house located at the bottom of a deep river valley is equipped with a pressure reducing valve apparently because the city water pressure plus the additional head pressure from the valley would exceed the safe 60 - 70 psi for residential plumbing (This *not *an automatic feeder for a hydronic system).
My question is: Does this not create a closed system? And if so, should there not also be an expansion tank for the hot water? I did not observe evidence of simmering or opening of the water heater T&P valve which would indicate that a problem exists.
An inspection I did recently had a pressure reducing valve and no expansion tank.
The TPR valve discharge was extended to the floor drain. Realtor commented that homeowner extended the piping because it would discharge regularly; also that his electrical bill (electric WH) was unusually high and asked me why that would be.
I told Realtor that homeowner needs to contact a qualified plumber to install an expansion tank and all should be back to normal.