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Thread: Temporary Water Pressure Loss

  1. #1

    Default Temporary Water Pressure Loss

    Looking for some help...

    Shallow well pump - likely the original in a 1990 house.

    Recently, the water will run fine and then pressure will lessen and then suddenly stop for approximately 10 - 20 seconds... then start again, after the pump starts for a couple of seconds. No air, the water will just start again with significan (usual) pressure. The pump does not short cycle. Nor does it appear to lose pressure without cause.

    I measured the pressure tank and adjusted the pressure to two pounds less than my cut-in pressure. This improved the issue, but did not eliminate it... and it is now getting worse (i.e. happening more frequently and water pausing for longer)

    Is it likely that my water pressure tank needs replaced?


  2. #2
    Master Plumber Redwood's Avatar
    Join Date
    Dec 2007


    More than likely a clogged nipple to the pressure switch or, a bad pressure switch.

  3. #3


    Thanks for your thoughts... I'll look at it again in the next day or two when I get a change.

    Thanks again!

  4. #4
    Moderator & Master Plumber hj's Avatar
    Join Date
    Aug 2004
    Cave Creek, Arizona

    Default flow

    Try removing more air from the tank. Your pressure gauge or air gauge may be inaccurate.

  5. #5
    Moderator valveman's Avatar
    Join Date
    Mar 2006
    Lubbock, Texas


    If the nipple on the pressure switch is not clogged up, I am afraid you may be tripping the motor overload. They usually reset automatically in 20 or 30 seconds, and may even start taking longer after a while.

  6. #6


    My pump (goulds jet plus) kicks on at 34lbs. The pump will then run for a few seconds (5-15) at near zero before the gauge kicks up to about 38lbs of pressure and sounds like water starts to flow. It seems as if it needs to create enough suction to open the check valve. I replaced the check valve about a year ago when I found a leak in the line just prior to the check valve (on the well side). I have had this current problem starting a few weeks after the check valve was replaced... it's just getting worse.

    Prior to replacing the check valve, I had air in the line... but now, I don't have air, just a pause in water - intermittently. Mostly after a long time of not using the water... it will run for a while, then pause, the pump will kick on for a few seconds and then a few seconds (15-30 seconds) later the water will come back on with significant pressure. Again, no air in the line and no short cycling of the pump.

    I removed the the copper tube to the pressure switch and cleaned it...

    Measured the pressure tank with the pump turn off and all the water out... and it measured 30lbs - 4 lbs less than when the pump turns on at 34lbs. Should I add 2 lbs?

    I'm thinking I should get a new pressure gauge that sits on the pump to see if the gauge is accurate.

    Thanks again for your thoughts!

  7. #7
    DIY Junior Member
    Join Date
    Aug 2008
    Caldwell, ID


    I just went through a similar problem. When a demand was placed on the system, the pressure would drop from 60 to 40 psi as it should. You could then hear the pump kick on, the pressure would hold at 40 psi for a moment, then drop to 0 and the water would stop flowing (try this in the shower). About 10 seconds later, the pressure would jump back up to 40, water would flow normally and the pressure would rise until it hit 60 and the pump shut off.

    After a few weeks of this, it changed suddenly to where the pump would kick on but it would take a couple minutes for the water to start flowing again. When it did flow, it was very slow (powerful trickle) and the pressure would read about 10-15 psi. With no demand, it would eventually refill the pressure tank and shut off at 60 psi again, but it would take as much as half an hour to refill.

    After searching the forums and talking to my local plumbing folks, checking amps and voltages and motor winding ohms, verifying the pressure switch and control box, and testing the flow at the top of the well (thereby absolving my well-to-house piping of any blame) I removed the pump (65 ft down). Turns out the check valve on top of the pump was bad. It was a spring loaded, central post/plunger type. The central post had worn almost through, the support bar across the valve had worn all the way through and the plunger had come loose. Because it no longer sealed, it allowed the discharge pipe to drain back into the well to the static water level when the pump was not on (while the check valve on top held system pressure normal). This caused the early indication of the water stopping for a few seconds; the pump had to refill the discharge pipe.

    There came a point when the plunger came loose entirely and would be forced up against the discharge pipe when the pump started, cutting off most of the flow. This accounted for the long time before water flowed (took longer to get the water back up the discharge pipe) and the low flow when the water did start at the faucet.

    It may not be the cause of your problem, but it's a thought. Good luck.

  8. #8


    I returned to Lowe's this morning to look at the check valves. There were two different one's to choose from... One had a much stiffer spring than the other. I installed the one with the stiffer spring - thinking it was a better construct. Both stated they were for well pumps.

    Is it possible that my shallow well pump is causing a temporary water loss as it has to build enough suction to open the check valve?? If I replaced the check valve with a less stiff spring, do you think my issues would be resolved??

    Thanks again!


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