I have a submersable pump water system. It has worked fine ever since I've had it (4 years), but lately the pump wants to keep runnning and can not build up much pressure.
The pressure gets to about 30 psi, then won't go any higher. And the pump just keeps on pumping, trying to get the pressure higher.
Any thoughts?
Thanks,
James

Could be a faulty check valve is causing you to lose pressure as fast as you build it up. Cheers, tom

Jim, tell me more about how you are measuring "The pressure gets to about 30 psi," How high are you lifting the water? Most sump drain lines would nevcer have this high of a pressure. I'd check the discharge line to be sure there are no obstructions.

Bal, this sounds like a submersable house pump and not a basement sump pump. Regards, Tom

What do mean by "check valve"? From the well, the water goes to the pressure tank, then there is a pressure gauge on the line between the pressure tank and a water softener.
Recent developments: When I shut the water off going to the house, and drain the pressure tank, I am getting very little water. I let some air pressure out of the tank, and it held some more water, but no where near the 20 gal. is says it holds.
Thanks for any advice.
-James

The bladder tank pressure should be set at 2 PSI under the cut in poiunt of the control box when the systems bled down and has no pressure in it. The check valve's located in the suction line downstream of the bladder tank. If it's not there it's a foot valve at the bottom of the well. Regards, Tom

Do you know how old the pump is? This may be due to an aging pump which can no longer pump beyond thirty pounds of pressure. Of course the pressure tank situation is also very strange. Be sure to check the pressure in the bladder at the top of the tank. As Tom said, it should be 2# below the point at which the pump cuts on. Still, that would not seem to explain why the pressure gets to 30# and stays there with the pump still pumping. Even one of the old non-bladder tanks will pump up to cut off pressure when mostly waterlogged if there is no demand on the system at that time.

Not sure about the check valve thing. My understanding of a submersible pump is it's a "one way street" to the pressure tank. So long as the pump is pumping, it makes no difference if the check valve is working or not. That only comes into play when the pump shuts off to prevent the water in the tank from simply flowing back down into the well.

The pump is only four years old. I have checked the air pressure in the tank. It was correct when the system was healthy, but because I am operating at such a low pressure (the pump kicks on at almost 0psi and kicks off at 28-30), I let some air out.
I had to set the pressure this low to make the pump kick off, otherwise, it is continually running.
A couple folks from around here have suggested the possibility of low water level in the well. This does not seem to be the case, because the pump has never actually stopped pumping water.

Sorry Tom, you are 100% correct. I read submerible and my mind jumped to sump pump. I know next to zero about wells so I'm out of here.

Quote:

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(the pump kicks on at almost 0psi and kicks off at 28-30),

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Which leads me to wonder if the pump control box isn't faulty. The pump does what the control box tells it to. The box should be tellint the pump to kick on at 20/30 PSI and off at 40/50 PSI. try replacing the control box and see it that doesn't solve the problem. Good luck, Tom

The pressure gets to about 30 psi, then won't go any higher.

That statement tends to lead my thinking away from the switch. The switch has the pump running but the pressure will not build any higher than 30#. The pump is only four years old so you would think that would not be a problem. I assume the well pipe is also only four years old, the tank is four years old, etc. However, if the pump is running and the pressure is not going above 30, then it would seem you have to be losing water somewhere. I would do this. Reset the switch so the pump is set to cutoff above thirty. When you get to thirty, turn on a faucet (preferably, one outside close to the tank/pressure gauge) and start measuring flow. You can use a five gallon bucket to see what you are getting in gallons/minute. Your pump should be able to hold at least close to that thirty pounds and deliver at least four or five gallons/minute. It it cannot, then I would start looking at where you are losing pressure or volume.

BTW, I would agree that the water table would not seem to be the problem. However, measuring gallons/minute for several minutes would at least show you that the pump is able to deliver water for some period. IF your pump can deliver 100 gallons in, say, twenty minutes then your pump and water table would seem to be OK.

Jlisenbe, your answer shows much thought and I agree but how do you explain the pump cutting in at 0 PSI instead cutting in at 20 or 30 PSI? I would start at the control box and go on from there. Regards, Tom

(the pump kicks on at almost 0psi and kicks off at 28-30), I let some air out.
I had to set the pressure this low to make the pump kick off, otherwise, it is continually running.

Good point Speedball. I can only guess that the user, in adjusting the cutoff down to 30, may have pushed the cut in pressure down as well, although you are right that near 0 seems hard to explain. At any rate, checking his well flow over a period of several minutes would at least rule out a few possible problems. It still seems to me that the pump not being able to generate more than 30# of pressure points to a faulty pump or some leak somewhere that prevents pressure from building as high as it should.