I checked the water pressure (in our recently acquired mountain house) using a gauge (with maximum indicator) that you attach to a hose bib. I was shocked to see the pressure going as high at 90 psi, but also at least as low as 50 psi.
This is a municipal water system in a mountain area with many hundreds of feet of elevation differential, and we are about 800ft below the town center. So I imagine the water from the street is very high pressure indeed. The pressure reducing valve is a Zurn-Wilkins Model 70, something like:
(my valve is just marked Model 70, not 70XL).
There IS an expansion tank on the water heater, which I installed just after moving in - although it might need the pressure adjusted.
Do I have a problem ? I imagine 90psi is too high.
How likely is the problem simply that the valve has fallen out of adjustment ? Seems unlikely, since I'm seeing so much variation.
If the answer to #2 is "not very", should I simply buy and install a new valve (about $150), or consider repairing the valve ? It appears they sell a re-build kit, but the price is about half that of the new one. But it avoids the installation procedure, I suppose.
Is it possible that this is the town's responsibility, and not mine ? The valve is in the basement, where the water line comes up from underground, just after the main shut-off.