New 44 gallon pressure tank At empty, tank reads 38 psi, pre charged at factory, and doesn't change.

Pump comes on whenever a faucet turns on. Just installed New piping from Pump to tank at 1 inch, and adapted to the tank's 1 1/4.

Plastic protector was removed

Not sure if the bladder is just stuck closed from storage ot what...

There is no filter between the tank and the pump.

  • what is the water pressure?
    – Jasen
    Commented Apr 10 at 22:43
  • Pressure on the pump is set to 30/50, and it is trying to keep that, it is a new pump. Commented Apr 10 at 23:34
  • I can get maybe a half gallon out of the system from 50 to 30 before the pressure suddenly drops to 0. Commented Apr 10 at 23:40

1 Answer 1


At empty, tank reads 38 psi

Pressure on the pump is set to 30/50

The air pressure in the empty tank (no water pressure) needs to be lowered to 27-28 PSI for a pump cut-in pressure of 30 PSI.

The 38 PSI pre-charge is suitable for 40 PSI cut-in, which is the highest in standard use, so people with 30 and 20 PSI cut in can just bleed off air to get to 28 or 18, rather than them sending out with 18 and people with 30 and 40 having to pump it up. People with 50 PSI cut-in are operating off the tank charts anyway, so they get to pump. Or they don't bother and waste half the tank capacity...

  • So to fix this just bleed air out of the Schrader valve until the pump starts?
    – Jasen
    Commented Apr 11 at 0:21
  • That is not what I wrote. Drain all pressure from the water side, bleed air to a measured pressure of 28 PSI. Turn on the pump, let it come up to 50 PSI and shut off. Then turn on a faucet and let it run. If the pressure goes from 30 to zero as the pump is turning on, take it down to 27 PSI and try again. The extra 2-3 PSI are to allow the pump time to start pumping without all the water in the tank being exhausted.
    – Ecnerwal
    Commented Apr 11 at 0:26
  • Not what you wrote but should work, it's using the pump switch as a pressure gauge.
    – Jasen
    Commented Apr 11 at 1:19
  • 1
    Doing it right is no more effort than doing it wrong (you'll have an unknown amount of water in the tank, since you're starting with the pump power on and the pressure switch shut off.)
    – Ecnerwal
    Commented Apr 11 at 1:27
  • 1
    Thanks Ecnerwal! It works now! Commented Apr 11 at 2:39

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