Jet pump stutters when starting

[Nate Aller]

We have a Gould JS10 1hp jet pump. This replaced our original 1/2 hp jet pump to pump water from holding tank to house which is uphill. Originally we had a filter between the jet pump and pressure tank which caused a lot of resistance and this pump shuddered when starting. We now bypass the filter but the pump still stutters when starting as if there is still resistance. Any suggestions for how to remedy this or any other thoughts as to what would make the pump do this? I'm told it is not good for the pump.

 

[Valveman]

I am guessing "stuttered" means kicking on and off rapidly? If so the pressure switch is probably just too far from the pressure tank.

 

[Sponsor]

 

[Nate Aller]

Thank you Cary. Are there any parameters about how far the pressure switch should be from the pressure tank? Ours is 56 1/2" inches away measure diagonally since we moved the pump up on a shelf to make it easier to access it.

 

[Reach4]

Another interpretation of your stutter would be there is a single momentary drop in pressure as the pump starts. That would mean your air precharge is too high. A jet pump takes time to build pressure, so it is common to have to set the air precharge maybe 5 psi below the cut-in pressure.

I just looked at you photo. I suspect Cary's interpretation was right. I don't see your pressure switch. Also, it is not normal to have a cartridge filter between the pump and the the pressure switch or pressure tank. If the filter gets clogged, the pump can run forever.

 

[Valveman]

Yeah way too much happening between the pressure switch and tank. You even have a filter there? Just get a new pressure switch and mount it down where the drain faucet is on the tank. You can wire around the other pressure switch and not have to take it off. There is a wiring diagram for that in the instructions for the PK1A kit under "jet pump".

A jet pump will pick up just as fast as any pump as long as it has a foot valve. With drive points and check valves higher up sometimes it takes a couple seconds to prime again. So it really isn't good if a jet pump doesn't pick up instantly.

 

[Reach4]

I was thinking to cap the existing pipe to the pressure tank at about the tip of the red arrow. Put a tee at T, and run a new pipe to the pressure tank. If the tank uses a 1-1/4 input, I would run 1-1/4 from the tee that holds the new pressure gauge G. The piping from T to the pressure gauge could be whatever size... 3/4 or one inch or even 1-1/4 .

You can see that the pressure gauge pressure will be very close to that in the pressure tank, so will not jump around. So that will be ideal in that the pressure tank