Pressure Switch turns on and loss of pressure and flow

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Wwkat54

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I currently have a issue that I am trying to resolve. Once the pressure switch engages at the cut-in pressure ( 40PSI) it remains static at 40 for a couple of seconds then drops to zero psi for a few seconds ( maybe 5 ) and I lose water flow. Water then returns to 40 PSI and continues to climb until cut-off at 60 PSI. Pressure remains static and holds until water is used.....what could be the problem? What test can I run to find my issue? Is it a start capactior or run capacitor?

Below are the new items I have installed on the well to fix my low flow issue that took place originally. After installing the new items, my normal pressure in the house returned as usual and everything seems find...except for this.....any help is appreciated.

  • Installed new bladder tank ( set at 38 PSI)
  • Installed new Pressure switch ( 40/60)...did not change orignal brass nipple that attaches to pressure switch.
  • New Pressure gauge
  • New Check valve between well cap and pressure tank.
 

Reach4

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Submersible pump? Could be start cap.
Jet pump? Change precharge to 36 PSI.
 

LLigetfa

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Calibrate your air pressure gauge. I suspect it reads different from the water pressure gauge. I suspect you shaved the 2 PSI too close and the tank is empty when the switch closes.
Remove the checkvalve between the well cap and pressure tank assuming it is a submersible pump. Depending on the depth to the static water level, preventing pressure from holding the checkvalve in the pump causes the water column to fall. There is then a hesitation as the water needs to refill the pipe.
 

Reach4

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It’s a submersible pump?

How can I check to see if the start cap is bad?
Find out what the capacitance should be. Then either buy a multimeter that can measure that level of capacitance +50%, or buy a new capacitor and swap it out. I am not a pro.

I would expect a weak start capacitor problem to be somewhat variable.

Another possibility is that you have an above ground check valve, and somehow the water is draining out of the drop pipe. Then there is a delay to refill the pipe. Do you have an above-ground check valve? Maybe show us a photo of the stuff before the pressure tank.
 

Wwkat54

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It is a submersible pimp and it’s about 500ft deep. I do have a check valve above ground that the pressure switch and Pressure Gauge are tied into.

I have a volt Meter and will check out the specs on the capacitor.
 

Valveman

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If the start cap was bad the pump would not just hesitate to start, it would trip the overload. I agree with removing the above ground check valve. However, with the pressure switch screwed into the check valve, makes me wonder if you have a diaphragm tank or an old standard galv type tank?

My guess is when you remove the above ground check valve the pump will come back on even if you are not using any water, because the check valve at the pump has failed. But you might get lucky and removing the top check may allow enough pressure on the lower check to make it start working again.

And if the check valve is worn out, you are probably cycling the pump on/off too much, as that is what destroys check valves.
 

Reach4

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If the start cap was bad the pump would not just hesitate to start, it would trip the overload.
So there is not a time when the cap is failing, but not yet failed, that the motor would not just delay? I guess if such a time existed, it would be a very variable delay and not a fairly consistent delay.

Wwkat54, it sounds as if you should budget to get your pump pulled and the check valve above the pump replaced, or the hole in the drop pipe gets fixed. I don't know if you should get that done soon to save the existing pump, or wait until the pump fails since pulling the pump is a big enough expense that you would replace the pump anyway.

To work around until you get the work done, maybe drop your precharge to 5 psi below the cut-in pressure. Maybe tighten up the differential from 20 psi to something less?
 
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Valveman

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Motor either gets up to speed or it doesn't. A delay in motor start would cause high amperage and the overload to trip. The delay is in how long it takes to get water to the surface, not how long it takes to get the pump/motor started. You could check this with an amp meter.
 

Wwkat54

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Problem Solved!!!

Adjusted the air bladder to 36...pressure and flow stays consistent. Thanks again for all of your helpful insight and solutions.
 

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I think you still have a check valve problem. All reducing the air in the tank does is give a little more time for the water to get to the surface. But if the bottom check is working properly, water pressure should start to increase the INSTANT the pump comes on. If not, you still have a problem.
 

LLigetfa

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If the water column is falling in the drop pipe as we suspect, then when the pump starts against no pressure, it could be in an upthrust condition that could hasten the wear on the pump. There could also be water hammer against the topside check valve that hastens its demise as well.
 

Reach4

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What should Wwkat54's action item be? Get the problem down the hole fixed now, or get as much use out of the pump before it fails as he can? Odds are, when he gets a pump 500 ft down pulled to fix the check valve or drop pipe hole, they are going to suggest a new pump -- at least if the pump is out of warranty. If he gets it fixed next week, should he say they should put the existing working working pump down the hole?

So should he just budget a new pump for 4 months or 4 years from now, or should he call the well service soon?
What should he budget for a fix next week, putting the pump back, or 4 years from now with a new pump?
 

LLigetfa

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Maybe there is no problem down the hole (yet). Won't know until the topside check valve is removed. The check valve in the pump might seal if it has the full pressure against it.
 

Reach4

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Maybe there is no problem down the hole (yet). Won't know until the topside check valve is removed. The check valve in the pump might seal if it has the full pressure against it.
Good point. Removing the innards of the check valve could be cheap diagnosis. And there is a significant possibility that the check valve at the pump would start working. But suppose for now that the pump then cycles one minute on and one minute off with the topside check valve removed? He should restore the topside check valve and then do what?
 

Valveman

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500' setting probably has multiple check valves down the well. Most likely the check at the bottom on the pump is the problem. If it is not causing a water hammer on start up and the delay in water can be adjusted for so you can live with it, I wouldn't fix anything until it stops working. It maybe causing a water hammer between the pump and the second check up the well, so you are not hearing or feeling it. That can cause an upthrust condition as LL says, and it can also shatter a thrust bearing in the motor. But I wouldn't fix anything until that happens. Because like has been said, when you pull a 500 footer, you don't want to just put in a new check valve and not replace the pump while you are at it.
 

Reach4

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I currently have a issue that I am trying to resolve. Once the pressure switch engages at the cut-in pressure ( 40PSI) it remains static at 40 for a couple of seconds then drops to zero psi for a few seconds ( maybe 5 ) and I lose water flow.
One more diagnostic question:

Is this delay present if the pump had run 10 minutes ago, or could it be that the full 5 second delay only happens when the pump has not run for several hours? Or something in between?

I understand that the reduced precharge is keeping the water pressure from falling off, but you may still see a delay on the pressure gauge before the needle starts rising. I wish I had asked before you dropped the precharge, because then it would have been more clear.
 

LLigetfa

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500' setting probably has multiple check valves down the well
Those that are below the static water level should not draw a vacuum as would the ones above the water level and so are lesser sins. We don't know where the water level is. One cannot assume just because the well is 500 feet deep or the pump hung at that depth, that the water is that low. Often a well needs to be drilled that deep to hit an artesian aquifer.
 

Valveman

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Those that are below the static water level should not draw a vacuum as would the ones above the water level and so are lesser sins. We don't know where the water level is. One cannot assume just because the well is 500 feet deep or the pump hung at that depth, that the water is that low. Often a well needs to be drilled that deep to hit an artesian aquifer.

True! But I will bet at least one of those check valves in the well is above the water level, just from the way it is acting.
 
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