Yard irrigation 3/4 horspower jet pump system problem.

Warren F
by Warren F
The system consists of the electric motor and pump, 15 gallon tank, pressure gauge, and on/off pressure switch. The tank is set at 38 psi and the pressure switch at 40/50 psi. The pressure gauge shows at least 50 psi. I just had the pump repaired and I reinstalled it to the system. There are no leaks from the pump or pvc piping and connections. The pump cycles w/o any problems when it has a full water pumping load, but if I use the water very sparingly (e.g. filling a small pail), the pump cycles on and will not shut off when I turn off the water. If I then open the water faucet full to get full pressure, and then turn the water off, it will shut itself off. Could I have a pressure tank problem or whatever. All thoughts greatly appreciated. Thanks
  3 answers
  • KMS Woodworks KMS Woodworks on Apr 27, 2012
    When you use a little water and then close the valve the pump runs for how long?....with no "demand" on the system the pressure should climb back up until the pressure switch trips and the pump shuts down.. If the pump continues to run under no load then the pressure switch may need to be adjusted / replaced.

  • Sounds like a switch control issue or a waterlogged tank. But if the tank pressure is not set the same as the pressure switch that can cause all sorts of issues. I would suggest you increase the pressure on the tank bladder to 45 psi. I assume your turning the pump on at 40 and off at 50, also I would increase the spread to at least 40/60 psi range. Which is typical for most jet style pumps.

  • Warren F Warren F on Apr 28, 2012
    Thanks for the quick replies. I'm starting to think that the problem may be in the tank. When I took the tank off the pump (for motor/pump repair) the water in the tank shot out like a fire hose. In the past this had never happened and that included a couple of different tanks. I've tried adjusting the pressure switch downward in pressure, so that may also be my problem. I'll readjust the pressure upward. Let's see what happens.