Water Well and Pump Repair/Well Surge


QUESTION: Hello Robert,

I have a well system that feeds two houses from one well. The well bladder tank is in the lower home approx. 200 feet from the upper home. The diff. in elevation is about 20'. The well is situated between the two houses and is 205' deep with the pump hanging at 165' 3/4 hp 10gpm. the well is rated for 25gal per min.
The upper home is Tee'd into the water line near the well and there is no check valve at the tank inlet at the lower house so the pressure in the tank can act on the upper house. The upper home has a swing check where the water enters the house. The well pump has a new check valve at the pump.
The cut in pressure at the lower house is set to 40# and cuts off at 60#
I recently drained the tank and filled the bladder to 38psi.
The problem I am having is a severe water surge. I have a pressure gauge on the well or supply side of the check valve and can watch the gauge bounce from 40# to 80# i say bounce because that's what i see, the gauge  bounces. Also i can hear the check valve opening and slapping shut on each bounce.
I'm not sure if the pump switch is doing this because i'm always at the upper house when it happens. I ask the people in the lower house if they hear the switch clicking and they tell me no. It does happen at odd times and sometimes when i'm running the water and sometimes when im not running water.
Thanks for any help you can give.

ANSWER: You only need one check valve and that is the one at the pump.  Never use a swing check valve on pressure systems.  They hammer and cause what your experiencing.  With only 20' elevation difference, that's only 8.6 pounds difference.  Remove the swing check and see if that fixes the problem.

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QUESTION: Hello Robert

I replaced the swing check with a flow check. I still have the same problem.
I posted a youtube video so you could see whats happening.

A little more info if this helps.
This problem started after replacing the well pump. We thought it was bad because we could here it running but were only getting very little water. We installed a new Gould 10GS07422C pump.But after replacing it we had the same problem. We decided to drop the pump lower in the well. As we were pulling the pump I noticed a check valve just below the pitless adapter. I removed the check to inspect it and found the nut missing from the limit stem and the check could block flow in this condition. I removed the check at the pitless adapter and set the pump back without lowering it. We instantly got a fresh supply of water when we started the pump.
So the only thing that is different is the new pump and no check at the top of the well. As I said we never had this problem before, with the old pump.
Link to youtube Video Below:

Thanks for all your help.

ANSWER: I can't begin to tell you how much damage that is doing to your motor.  Cycling like that builds tremendous heat and will soon take out the motor.  The check with the nut missing would act just like a swing check.  So you have removed the bad check under the pitless and have removed the swing check. That's good.  Now, where is the tank in relation to the pressure switch?  They should be together, not more than 3' apart if at all possible.  If further, that condition can cause the same result you have in the video.

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QUESTION: The pressure switch is located in the lower home and is connected in the normal configuration, right at the bottom of the tank at the water inlet.

In that case, I think your tank is totally waterlogged.  Unless there is another check valve somewhere that you don't know about.

Push on the top of the tank in a sideways direction to see how hard it is to rock.  Not far enough to break any pipes, just to see how heavy it feels.  If it's waterlogged, it will be very heavy.  If it is still good, it should be very light.  Just slightly heavier than the tank would be when empty.  If it's light, turn off the pump, open a faucet and wait until all water flow stops then with a tire gauge, check the pressure in the tank.  It should be two pounds lower than the pumps turn on pressure.

Water Well and Pump Repair

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Robert Tabor


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