Shallow well jet pump pulling vacuum on discharge side when shutting off.

[Kev1900]

I replaced my shallow well jet pump last week because my 10 yr old one finally rusted out. New pump worked great for a week and then all of the sudden, when discharge side is closed off, pressure builds up, pump shuts off, but then a rushing of water from supply side and a vacuum on the discharge side enough to collapse hose and then the pump comes on again, shuts off, same rushing water noise from inside the pump housing, and pump turns on again. Like I said, everything worked perfect for a week, plenty of water volume and pressure when I am irrigating.
Eco Flo 1hp shallow jet well pump from Home Depot. Brass check valve 1.5 ft. from inlet mounted horizontally under ground. No leaks that I can find. everything dry when pressurized. 3 well points 9 ft. apart 20 ft. down in parallel.
Thank you in advance for any help!

 

[Reach4]

I don't have any experience with jet pumps, but I would wonder if your check valve is not working.

 

[Sponsor]

 

[WorthFlorida]

I had a $175 2" brass check valve would never completely close. Each time the pump turned off it lost prime as you could hear the water rushing back down the well.
On another pump I would occasionally lose prime. One time I caught it stuck open. A metal tooth from the dril bit had jammed in the check valve. I guess it would occasionally break lose then get sucked back up.

 

[Valveman]

Yep, bad check valve.

 

[Kev1900]

I replaced my shallow well jet pump last week because my 10 yr old one finally rusted out. New pump worked great for a week and then all of the sudden, when discharge side is closed off, pressure builds up, pump shuts off, but then a rushing of water from supply side and a vacuum on the discharge side enough to collapse hose and then the pump comes on again, shuts off, same rushing water noise from inside the pump housing, and pump turns on again. Like I said, everything worked perfect for a week, plenty of water volume and pressure when I am irrigating.
Eco Flo 1hp shallow jet well pump from Home Depot. Brass check valve 1.5 ft. from inlet mounted horizontally under ground. No leaks that I can find. everything dry when pressurized. 3 well points 9 ft. apart 20 ft. down in parallel.
Thank you in advance for any help!

Mystery solved!!!
My grandson wanted to help and thought palm seeds in the pipe would help. They worked there way to plug open the check valve. Evidently with the check valve stuck wide open. when the pump shuts off, the columns of water from the well points, rush down and suck all the water out of the pump and hoses. Found it when I went to mount the check valve vertically instead of horizontally.
Thank you to everyone who replied!!!!!