Jet pump problem - rapid fire pressure switch

Help Support Plumbing Forums:

Danajac

Member
Joined
Mar 26, 2021
Messages
5
Reaction score
1
Location
Missouri
My employer has a jet pump on a shallow well that has never operated correctly. I was not involved in the set up of the system, but I'm trying to troubleshoot it and get it working.

Pressure tank seems okay, and I set it at 28 psi, as per the instructions on the pressure switch on the pump.

When the pump was turned on, it would reach the cut-out pressure, then rapid-fire on and off continuously, until the power was turned off to keep it from burning up the points. Upon contacting the pump company, they assumed it was a bad pump or pressure switch, and sent us a whole new unit.

When I hooked up the new pump, upon throwing the switch (after draining the pressure tank to 2 psi below the set cut-in on the pump), the pressure switch on the pump did the same rapid-fire. I then realized that the system had a check valve on the discharge, above the pump.

Today, I removed the check valve, and replaced it with a ball valve. This time, when turning on the pump, it ran, but when the pressure gauge on the tank reached about 45psi, it started doing the rapid fire on and off.

I am now assuming that the pipe going down in the cistern does not have a foot valve on it, or it is leaking. One reason I concluded this is I could hear the water running back down the pipe when I turned off the pump. So, I plan to install a check valve between the cistern and the inlet of the pump.

Is that likely to solve the problem? Is that a sufficient substitute for having an operative foot valve?
 

Valveman

Pump Controls Tech
Professional
Lifetime Supporter
Joined
Jan 6, 2010
Messages
927
Reaction score
217
Location
,Lubbock, Texas
Yep! You need a check valve on the suction side as close to the storage tank as possible. If that does not stop the clicking then the pressure switch, being mounted on the side of the pump, is too far away from the pressure tank. One of those things will stop the rapid cycling. Then you need to find out how to stop the repetitive cycling from everyday use. :)

 

Danajac

Member
Joined
Mar 26, 2021
Messages
5
Reaction score
1
Location
Missouri
Installed check valve on suction side. Pump kicked on fine, pressure built up to 40-50, pump kicked off. Then I ran the water and let the pressure drop. At about 28 psi (on the tank gauge), points on the pump pressure switch started bouncing again.

Any ideas? There is a slow leak at the pump inlet.
 

Zanne

Well-Known Member
Joined
Mar 23, 2013
Messages
2,094
Reaction score
279
Location
,
Is the pressure tank new as well? Also, is it possible the wires going to the pump are damaged in any way? I had some chattering a bit when my wires were burned. I also had the same issue when my pressure tank had gone bad. I'm planning to switch to a cyclestop valve once I get other essential things done first.
 
Top