Losing Pressure

[holiday]

Hi,
I have a new 1hp shallow well jet pump, new pressure switch, new check valve.
When the pump is primed it reaches 50psi and switches off. However, in each of the first two hours, it loses about 8 psi and then about 2psi per hour. Once the zones are run and finished it loses all 50psi within 3 hours?? There are no visible leaks.

 

[WorthFlorida]

Where is the pressure gauge?
Is there a pressure tank?
This is only for irrigation?
Is there a check valve before the pump inlet?
Is a master valve used?

You should use an irrigation pump, not a jet pump. No pressure switch or tank is needed.

 

[Sponsor]

 

[holiday]

Hi,
Pressure gauge is on the pump
Yes Pressure tank 28psi
Irrigation only
Check valve before pump on inlet
No master valve

Thanks for any help

 

[WorthFlorida]

Could be one of the zone valves is leaking. I have had a bad check valve. You may hear water rushing back down the well.

 

[holiday]

Where is the pressure gauge?
Is there a pressure tank?
This is only for irrigation?
Is there a check valve before the pump inlet?
Is a master valve used?

You should use an irrigation pump, not a jet pump. No pressure switch or tank is needed.

Will have to check the valves. Thank You

 

[holiday]

Checked valves but no leaks. Changed diaphragm on all valves, still loses pressure over time while pump is off. When it reaches zero on the gauge and you wait even upto 12 hours and power up the pump, it primes in 30 second. Leak must be on discharge side???

 

[WorthFlorida]

Checked valves but no leaks. Changed diaphragm on all valves, still loses pressure over time while pump is off. When it reaches zero on the gauge and you wait even upto 12 hours and power up the pump, it primes in 30 second. Leak must be on discharge side???

Prime is lost on the inlet of the pump. I had a new $170 2" brass check valve leaked when it was brand new at the inlet of the pump. When the pump turned off you could hear the water rushing down the well But you had to place your ear on the check valve. To lose pressure on the irrigation side is not so bad. It'll take a few seconds for the water to get to the sprinklers as long as the pump remains primed.

I think you're losing pressure because the water is back flowing to the pump and down the well. If the inlet pipe had a leak anywhere, the prime would be lost and the pressure would remain.

You should have a shut off valve on the outlet side. You can close it when the pump is off and see if the pressure drops. If it does not, open the valve and if the pressure drops, then water is going back down the well.


With a closed check valve, water will remain in the pipe at the check valve. The outlet side may go dry but prime should not be lost.

 

[holiday]

Prime is lost on the inlet of the pump. I had a new $170 2" brass check valve leaked when it was brand new at the inlet of the pump. When the pump turned off you could hear the water rushing down the well But you had to place your ear on the check valve. To lose pressure on the irrigation side is not so bad. It'll take a few seconds for the water to get to the sprinklers as long as the pump remains primed.

I think you're losing pressure because the water is back flowing to the pump and down the well. If the inlet pipe had a leak anywhere, the prime would be lost and the pressure would remain.

You should have a shut off valve on the outlet side. You can close it when the pump is off and see if the pressure drops. If it does not, open the valve and if the pressure drops, then water is going back down the well.


With a closed check valve, water will remain in the pipe at the check valve. The outlet side may go dry but prime should not be lost.

Hi,
Thank you for your help. There is no valve on the outlet side to close. But you think there is a leak in the suction side?? Outside there is no visible leak and the check valve is a new pvc valve, may be a faulty check valve?? I will check if I can hear water going back down. Thanks

 

[WorthFlorida]

The pipe underground could have a leak. How old is the well Or are you pumping from a lake?

 

[holiday]

The pipe underground could have a leak. How old is the well Or are you pumping from a lake?

Hi
Pumping from a well, house is 20 years old. So just wanted to be clear, I power up the pump and it reaches 50psi within 30 seconds and cuts off. I am assuming that all the pipes from the pump to each irrigation valve are full of water. I then disconnect the power. The pressure gauge on the pump starts to drop. After about 7 hours the pressure is zero. I have left it like this for 3 days and when I power the pump up, it reaches 50psi within 30 seconds. If the water was back flowing to the well, I don't think it would prime that quickly?? So maybe there is a leak between the pump and the valve.
Thanks

 

[WorthFlorida]

At the zone valves, there is hand tighten screw that allows to manually open the zone valve. In the video its shown on the right side. This screw any have come loose keeping the valve to not fully closed.

A common problem is the diaphragms dry out and do not seat well or they crack from being too stiff.
For some reason the youtube is not allowing a link to the video. Just copy and paste.

youtube.com/watch?v=5rokXHhxRSw

 

[holiday]

Thank you, will check.