Goulds 1/2 hp, jet pump, discharge pressure

I had a Goulds 1/2 hp shallow well jet pump that I had checked the cut in and cut out pressure to be 25/38 psi. Everything I’ve read states that this number should be closer to 30/50 psi. I was wondering if anyone has any details on these pumps that might clarify this. Just wondering if this should be reported as a problem that needs attention. The water pressure in this house was horrible as a result.



It is common for the pressure switch to be set at 20/40, 30/50, or 40/60. I would say that someone has tried to increase pressure by adjusting it. You can usually get 8-10 lbs of adjustment (increase) on a switch. Stange pressure differentials sometimes indicate that someone has messed with the small screw ( Square D ), which if I remember correctly is the cut in only, the tall screw raises the cut in and out screw and maintains the 20lb differential. In any case I’d want to know what the gpm are and what size the storage tank is. If there is adequate water volume, you could hold the contacts of the switch closed to increase presssure to determine that the line to the switch is clear, not corroded or partially plugged at the fitting in the pump housing or at the switch. Then recommend a replacement switch 30/50 or 40/60.

Then, report that and refer it out to a qualified professional.

Of course plugged aerators, showerheads, flush valves, and distribution piping could also be the cause of low pressure.

Note also that the possible discharge head of any centrifugal pump can be affected by the suction lift as well. So, if the water table at the well is low for some reason, the pump will not perform as well.

Sorry. Here are a few more details on the pump and tank. The pump is only putting out 2-1/2 gal/min, I think for a non-submersible jet pump this should at least be 6 gal/min. The pump is connected to what looks like a 12 -14 gallon horizontal pressure tank. There was also a water treatment system inside the home.

Attached a picture file using the attachment icon. Not sure how the “Attach Image” function on this group yet.

Thanks for all of the feedback.



First off, that looks like like a single pipe pump. With nozzle and venturi, you’re looking at like MAYBE up to around 30 feet of depth.

There are too many variables to consider without having the specific knowledge to perform a more indepth investigation. Sure the intake can be clogged, but I suspect that the pressure switch was jacked with, or may be defective.

Shallow wells are most susceptible to overdrafting and contamination.