We moved to a house that has well water a couple of years ago - my first experience with that. It worked fine for most of our time here, but a couple of months ago we started noticing occasional drops in water pressure. Usually in the shower, though the kitchen sink flow is also noticeably difference sometimes. At first, we all just kind of ignored it, assuming it was because multiple people must have been showering at the same time. But over time it became more common, and we figured out it wasn't due to multiple simultaneous showers. And within the past week or two, occasionally the pressure drops enough that it's hard to shower some times. When the pressure drops a lot, it usually comes back after a couple of minutes, so we can wait it out.

We have a Well-X-Trol WX-302 pressure tank and a Grundfos pump (sign says model # 16505412 but can't find a reference to that online, so maybe it's wrong). The pump seems to have been installed in the mid 90s. The pressure tank has a pressure gauge next to it that seems to always read about 82 psi, regardless of the time of day and regardless of whether we're experiencing low pressure in the upstairs shower or not at the moment (I have a security camera pointing at it, so I can check it from my phone). It is so consistent that I'm getting a little suspicious of it.

Well-X-Trol WX-302 pressure tank

Pressure Tank connection and pressure gauge

Well pump info

Pressure gauge always looks like this with about 82 PSI

What is the likely cause of this variable pressure?

  • 1
    If that gauge is really working, then that pressure is way too high. Extra-high pressure means the pump is running more than necessary, using up the pump's life quicker. Typical well pressure switch ranges are 30-50 lbs, or 40-60 lbs. The switch could be adjusted: I set mine to 50-70. But 82 is too high. Commented Apr 1, 2023 at 1:28
  • I'm suspicious of the gauge, because it never moves. So I can't say I know what pressure it really is at. I presume that gauge is just for human readability, and the pump runs off a different pressure sensor?
    – Doug
    Commented Apr 1, 2023 at 1:48
  • It certainly looks old and rusty. Probably a first step would be to depressurize the system and replace that gauge, so you see what's really happening. Commented Apr 1, 2023 at 1:50
  • When you replace the gauge install a small ball valve in line with it so the next time it is an easy replacement.
    – Gil
    Commented Apr 1, 2023 at 3:16
  • I would guess that your well installers, through either incompetence or malfeasance, put the serial number in the model number box, rather than let you know what model number you had. The malfeasance angle is "so you couldn't just buy a new one of the same model when that one died." At nearly 29 years of age, it's probably time to consider replacing it.
    – Ecnerwal
    Commented Apr 1, 2023 at 14:12

2 Answers 2


It turns out that it was a failed pressure switch. The broken visible pressure meter was obviously a problem, but didn't cause the actual water pressure issues. After the plumber replaced the switch (and the visible meter, for good measure, since I had a new one), everything is back to normal.


If that gauge doesn't move I would suspect it is stuck. You could try rapping on it to free it. As far your low pressure, your pump is old enough that it could be failing. I'm not sure where you are located but if it's a shallow well and it's been dry, it may not be able to replenish fast enough. Most likely it might be time for a new pump.

  • We're in NJ, and it hasn't been dry recently (rarely is, here in NJ). As for not being able to replenish fast enough - it does recover pressure while the shower is running, so it's not like we see dropping pressure through the duration of heavy usage (if having a shower is 'heavy usage')
    – Doug
    Commented Apr 1, 2023 at 1:30
  • Does the pressure recover fully when the shower is running?
    – JD74
    Commented Apr 1, 2023 at 1:38
  • No - it doesn't seem to move at all when the shower is running, which is why I'm suspicious that it's not working.
    – Doug
    Commented Apr 1, 2023 at 1:48
  • And for what it's worth, I banged on it a bit to see if it would un-stick itself and nothing happened.
    – Doug
    Commented Apr 1, 2023 at 1:49
  • I was referring to the pressure in the shower, not the gauge. There isn't any doubt that your gauge is bad.
    – JD74
    Commented Apr 1, 2023 at 1:50

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