1. margaret

    margaret New Member

    Dec 11, 2005
    Got a question about our pressure tank. We have a well and a 20 gallon pressure tank. The tank is set at almost 40 psi. The gauge reads it and when I check the pressure with a tire gauge from the top valve it read the same. When we run a large amount of water we "run out". We've found that if you turn the breaker off to the well for even just a couple minutes the water will run again. Sometimes for just a couple minutes but it runs out again. The other morning it was really cold out and we had problems all day. If you leave the breaker off for about a half hour it runs longer. I don't think we are actually running out of water. We have a new gauge and switch and are going to start there. Next thing is to replace the tank. Last year we pulled the pump and replaced wiring. The pump is not that old. But I've noticed that until you turn the breaker off and turn it back on the water will not run. Any suggestions. Thanks, Margaret
  2. Mike Swearingen

    Mike Swearingen New Member

    Jan 12, 2005
    Independent Real Estate Broker
    On Albemarle Sound In Northeastern NC
    It sounds like your pump is set for 20-40 psi cut-on/cut-off. If you're reading the presssure tank after it runs until cut-off, all that you're reading is the cut-off pressure (40 psi).
    The proper way to check the tank is to turn off the pump, drain the water pressure down, and then check it. It should read two psi below (18 psi) the cut-on pressure.
    If it's too low, air it up with a bicycle pump or portable air tank or compressor. If it won't hold that pressure, you probably have a shot bladder, and the pressure tank needs to be replaced.
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  4. Bob NH

    Bob NH In the Trades

    Oct 20, 2005
    New Hampshire
    Getting water after you turn the breaker off and on suggests a water supply problem. Let's find out about the system.

    Do you have a submersible or jet pump? If a jet, is it a deep well or shallow well jet pump?
    If a submersible, do you have a control box (meaning 3-wire pump)? Do you have a device called a Pumptec or something similar?

    When you run a lot of water and run out of water, are you getting low flow or no flow?

    When you run out of water is the pump still running or has the pump shut off?

    If the pump has shut off below the cut-off pressure of the pressure switch, then you have some kind of control that is shutting it off, or you have an overload device that is shutting off the pump. Small pump motors often have internal overlaod devices that automatically reset.

    If the pump is still running when you run out of water then you have either run out of water at the pump inlet, or have lost prime at the pump, or the pump has failed. Because it will restart after shutting off the breaker, I suspect that you have run out of water.

    If you have a submersible pump it is possible to run out of water if you have a leak in the line from the pump to the house. That is rare but must be ruled out if nothing else shows up.

    When checking the pressure tank for leaks, there are two modes of failure; the bladder can leak or the tank can leak on the air side. I replaced one a few months ago that was rusted through on the air side. The usual characteristic of a failed tank, or an improperly charged tank, is short runs between stop and start of the pump. That can cause the pump to shut off because starting the pump requires a lot of current that heats the motor which will cause its overload protection to shut off while it cools.

    If you don't find the answer, post back with system information and any new symptoms.
  5. speedbump

    speedbump New Member

    Jul 15, 2005
    Water well and pump tech.
    Riverview, Fl.
    Your changing the switch and gauge while they are already working won't help. And why did you change the wire in the well?

    I think Mike has the solution, low producing well. When you replaced the wire, did you measure the water level and the depth the pump was set at?

  6. Gary Slusser

    Gary Slusser That's all folks!

    Aug 31, 2004
    Wherever I park the motorhome.
    I know why you think it, you don't want it to be true, but what is the basis of your thinking that you aren't running out of water in the well? ;)

    Running out of water is usually never caused by the switch, the gauge or the pressure tank... so pinch yerself and anyone else as soon as you or they think it isn't a lack of water in the well. Then start water conservation ASAP, because to continue running a pump without water shortens the life of the pump motor in a fairly short period of time.

    Quality Water Associates
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