Lake water jet pump slowly loses pressure

[brad2145]

hi,

Have a 3/4 HP 2 line jet pump that pumps from our lake. Approximately 200 feet of waterline pumping up grade.

Noticed this year that pressure on pump starts off around 30 when using water then drops to 20 after 2 minutes then drops to 10 after 8 minutes. At this point pump sounds like it’s sputtering a bit and isn’t running smooth.

As soon as we turn water off the pump jumps back to 30 and runs smooth.

The pump is always running and isn’t cycling with the pressure tank.

I dove the other day and the foot valve looks clean and in good condition

Any ideas how to proceed?

Thanks

 

[LLigetfa]

If it cannot build pressure above 30 PSI to shut off, it is probably a clogged jet. You would have to lift it out of the lake to clean it.

 

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[brad2145]

If it cannot build pressure above 30 PSI to shut off, it is probably a clogged jet. You would have to lift it out of the lake to clean it.

Thanks for the reply.

The pump is in my house. Take water lines off and clean the jet pump?

 

[Reach4]

For your 2-line jet pump, the jet is in the lake (in the ejector).

 

[brad2145]

For your 2-line jet pump, the jet is in the lake (in the ejector).

Kept checking and the psi on the pump gets to 40 when there is no draw on the pump so I can’t see how that’s a jet or footclamp issues. It seems like the pump slowly loses suction power over duration of several minutes when a water tap is on.

 

[LLigetfa]

When a jet pump cannot make enough pressure to shut off, it is often due to a clogged or partially clogged jet. If you can't see it maybe you are not looking hard enough?

 

[Valveman]

My guess is a suction leak. Probably right where the suction pipe screws to the pump.