Pressure tank empty...pump runs...we get water.

[John in western WA]

Hi all. First post here.
Reading through past posts I've gotten some good insights about the issue I'm having with the well. Still, I thought I'd ask for help since none are exactly like my symptoms.

Specs:
Submersible pump 1.5hp (21 years old)
Depth 238'
Pipe is 1.25" pvc with galvanized couplings
80 gallon pressure tank
40/60 pressure switch. (Contacts are shiny)

Symptoms:
This morning there was a noticeable pressure drop at kitchen sink.
Checked pressure at tank (20psi)
Switched off pump and pressure almost immediately dropped to zero. ~4 seconds
Checked pressure on top of pressure tank. It was low (22 psi).
With pump off and pressure reading zero psi, I added air to increase to 38 psi.
Switch pump back on...
It gained pressure very quickly then couldn't get over the hump of 40 psi. Pump kept running but never got over 38 psi. Checked water at sink...water flowing as normal. Turn off sink. Back out at pressure tank ...still not getting over 38psi. Switch off . Whooshing sound as though water leaving the tank. Tap on tank..sounds empty and feel light when slightly rocked.

Summary: pump runs and we can get water but pump never shuts down. As soon as it is manually switched off pressure drops rapidly to zero.

My diagnosis: a bad pump or check valve that will require having the pump pulled.
BUT I've read here it could also be a trapped slug of air (hammering.) ???
Any thoughts or suggestions?
Thanks for any help.

 

[Reach4]

BUT I've read here it could also be a trapped slug of air (hammering.) ???

Sounds not credible for a submersible well pump. Maybe you read something about a submersible sump pump.

 

[Sponsor]

 

[LLigetfa]

Bad check valve would not prevent the pump from reaching cutoff pressure but a hole in the pipe would. Lifting the pump that might be 200 feet down is not likely a DIY proposition so it is time to call in a pump man.

My guess is the pump was installed with multiple check valves and their failure resulted in water hammer that caused the leak. Decades ago a lot of pump men thought that multiple check valves were a good idea. Unfortunately there are still a few that hold that belief.

 

[John in western WA]

Sounds not credible for a submersible well pump. Maybe you read something about a submersible sump pump.

Thanks. I went back and checked and sure enough...not a submersible. It was indeed a sump.

 

[John in western WA]

Bad check valve would not prevent the pump from reaching cutoff pressure but a hole in the pipe would. Lifting the pump that might be 200 feet down is not likely a DIY proposition so it is time to call in a pump man.

My guess is the pump was installed with multiple check valves and their failure resulted in water hammer that caused the leak. Decades ago a lot of pump men thought that multiple check valves were a good idea. Unfortunately there are still a few that hold that belief.

I was ready to be there tomorrow when they open so as to secure my place in line. Then my wife hears water running. Turns out what she heard was the neighbors pond pump BUT...
Going out to investigate, I saw an irrigation riser on the ground. I dug to check the base and sure enough...I must have hit it with a piece of rental equipment I was using this morning.
Going to get a 3/4 plug and hose clamps now...
Thanks for your response.
I feel like an idiot ....but a happy idiot that most likely avoided a new pump/ pipe or valve....not to mention the embarrassing and expensive diagnosis from the pump guy.
Thanks again.

 

[LLigetfa]

I assumed your troubleshooting steps would have included closing the main shutoff valve after the tank.

 

[John in western WA]

I assumed your troubleshooting steps would have included closing the main shutoff valve after the tank.

Thanks.
I have to admit I hadn't thought of that. I'm not sure I have a valve after the tank. There's a shut-off at the house we're water first enters.
Either way, I'm not sure it would have helped me in my particular situation. The well tank and control are nearly 100' from the well in a shed and also down hill from the well maybe 25 feet. There's a hydrant next to the well and all irritation water is distributed up there. There is a shut off there so in the future I'll know to shut that off during troubleshooting. Same with the house to rule out leaks there.
Again, thanks for pointing out the need for a shut off as part of the troubleshooting process.