Hi,
I am having a problem with my water pressure. Water tank and switch are ~20 years old. Well pump is about 5years. Problem is the water pressure intermittently drops to zero or near zero.

Yesterday I checked out my system. I adjusted the (bladder) tank air pressure to about 35-38 PSI, and the cut on to about 42 and cut-off to around 62. Everything worked fine for a couple of hours. Then the pressure started getting wonky. Here is a video of the tank and pump cycling.(https://youtu.be/85QqrfPiGyw) As you can see and hear, the cut-off/cut-on are about right. Immediately after the cut-on, the pressure suddenly drops to near zero (about 10psi in the video, sometimes to zero.)

Any suggestions? Do I need a new tank or switch? Hopefully, I don't need a new well pump!

 

My compliments on the video as it shows the problem perfectly. That's the good news.

The bad news is that is a very odd problem. In the video we can hear the pressure switch acting when it should. We can see the pressure gradually dropping when the pump shuts off. To eliminate any usage into the house... turn the valve off to the house to see if pressure still drops as fast.

If it does.... the most likeliest problem is a leaking foot valve in the pump.

What I find most puzzling and can't explain is why the pressure drops rapidly when the pump starts. The pressure gradually drops until it reaches the 40psi point, the switch closes and the pressure plunges.

I replayed the video ten times. I'm hearing something strange. The pressure gradually drops to 40psi, the pressure switch clicks, the pressure drops rapidly and the switch clicks again.

Normally I'm not long winded like this. I think the problem is you have a major water leak causing the pressure to drop when the switch shuts the pump off. Since the tank has pressure in it.... the gauge is going down slow as the pressure in the tank equalizes. At the point where the switch starts..... the pressure tank is empty and the pressure in the system just plunges. Since I hear the switch click twice.... my opinion is the switch is bad. It's not closing fully at 40psi. It closes fully on the second click when the water pressure is just about at 10psi.

It's either a bad pressure switch or a clog in the pipe that connects it to the system.

 

I will check out what the groaning is. How do I get the pump to cycle if I turn off the water to the house?

BM99

 

My apologies. I re-wrote my post so please re-read it.

The pump doesn't care if the water line to the house is shut off. It will still pressurize the tank.

 

I took a video of the switch in close up. It looks like it closes completely with cut in.https://youtu.be/JsbvCYOHBDI


I closed off the water to the house. The pressure stays at whatever it was when I closed it off. I waited a couple of minutes without a change. I also tried turning off the water to the house just as the switch closed at cut in at 40 psi. It stayed at 40 and didn't drop.

The groaning noise (first noise on this video) is water rushing through the pipes at the tank. The second noise is the noise of the water rushing to the house after the pressure dropped to 10.

 

Ok.... so you have something using water in the house since the pressure didn't drop when you isolated the house from the well.

I see the switch closing.... looks solid.... but what is that second click ?
At :10 - first click at 13: a second click

 

This may be a dumb question but was the house water turned off in the video in your first post. We are assuming it was but if you had a tap on to allow the pump to cycle on then we don't need to be looking for a leak. Let us know if all the taps were turned off when you ran the first video.