I just replaced an old Craftsmen shallow well jet pump with a Zoeller, same HP, but the pump is consistently switching off and on and not delivering 1/3 the flow it should. We set the new pressure tank to 18 PSI per the recommended factory 20/40 switch. However, we're pushing the supply to the house probably 300 feet horizontal and 50 feet vertical if I had to guess.

Roughly looking at it, I think the PSI is just too low. If it is 50 feet of head, that's about 21-22 PSI loss and I think the pump switch is just ineffective due to the line pressure being high enough. Does that sound about right?

The guy at the customer support said it didn't matter and maybe it was because my pressure switch is too far from the tank, but it is only about 2 ft because its mounted on the pump itself from the factory.

Any advice would be greatly appreciated, been banging the head for 4 days now.

  • Those pressure switches are usually adjustable. Maybe bump up to 30/50 or 40/60.
    – crip659
    Commented Feb 8, 2023 at 0:49
  • What's the model of the pump ? They are often rated for the head of water. Commented Feb 8, 2023 at 2:24
  • Crip, yeah that's what I'm thinking, at least 40/60 just to troubleshoot the lift issue and then whatever the max can be for any real pressure at the house. Rohit, its a Zoeller Model #1461-0006, 3/4hp, they publish how much it will lift on the suction side, but not the supply side. Commented Feb 9, 2023 at 1:37

2 Answers 2


thanks for the help on this. We bumped up the pressure a good 15psi or so and its working. Still need to tune it with the distance in the line and put a gauge at the house, but just having water flow consistently and a happy pump is a really good sign.

Cheers. Steve


If the pressure switch is located within 2 ft of the pump, and set to just 18 PSI, I don't see how any water can be pushed up with a head of 50 ft (which, as you state, requires 22 PSI to reach that level)!

If the pressure switch were located at the top of that lift, it would work correctly. Or, as you state, it needs to be set 22 PSI higher to accomodate that lift.

Two questions:

  • Is a shallow-well pump rated to lift that far?
  • Is sufficient voltage reaching the pump, through 300 ft of wire? What gauge conductors are in use?
  • 2
    The question is: is this particular shallow well pump rated for adequate output pressure. The other question is - is there sufficient water in the well?
    – Ecnerwal
    Commented Feb 8, 2023 at 2:38
  • I tried to find a max setting, and the only thing I can find are people setting some of these switches to over 60. I can't find any details on max psi setting from Zoeller. Some charts on similar pumps stop at 25ft lift mentioned, others go to 50ft. I know there is at least 12g at the plug, but the main line to the shed is likely larger, and I think its enough, because the pump will start and load just fine and its rated at the same amps as the pump for 20yrs. Plenty of water in the well. So it sounds like raise the pressure and see if it will lift past my estimated head lift issue. Commented Feb 9, 2023 at 1:52

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