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.


  1. Do I have a problem ? I imagine 90psi is too high.

  2. How likely is the problem simply that the valve has fallen out of adjustment ? Seems unlikely, since I'm seeing so much variation.

  3. 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.

  4. 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.

  • 1
    Ever considered that the water supply may be above you? I also live in the mountains and the water reservoirs are above where I live - called glaciers... Also the water supplies electricity generating plants so they understand height...
    – Solar Mike
    Commented Apr 15, 2023 at 8:14
  • Here in Auckland (NZ) the municipal water pressure can range from 45 to 145 psi, depending on where you are. And you almost always have a pressure-reducing valve in your house. The advice here is to reduce it to approx 70 psi Commented Apr 15, 2023 at 12:27
  • @SolarMike Yes, the water supply is definitely above where we live, probably 1000ft or so. That's why there's this pressure-reducing valve. Maybe the max inpout pressure is being exceeded. Over 1000ft, that's probably like 500 psi, right ? Commented Apr 15, 2023 at 15:18
  • Water pressure in the supply pipes here is about 9 bar. So every house, factory, workplace has a pressure reducing valve right after the main shut off.
    – Solar Mike
    Commented Apr 15, 2023 at 15:41
  • Which is exactly what I have. I'm thinking adjusting isn't the answer - it must be faulty if it's that far off. So repair or replace ? Commented Apr 16, 2023 at 4:02

2 Answers 2


90 is on the high side and should be reduced.

#2 is probably a two parter. Valve out of adjustment/worn out and the number of town people using the water at once.

Repair/replace will be your decision.

Town usually only goes to the street tee/water meter. Everything else comes out of your pocket.


Your water pressure regulator is broken or needs adjustment or you need to install one.

It will limit the high pressure to its setting, it will not increase the low pressure.

It is there to protect your plumbing from high pressures,

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