Malfunctioning Shurflo Extreme 5900 water pumps

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I am talking about The Shurflo Extreme 5900 5.7 GPM RV water pump. These are no longer made by the way.

My copy of the pump was cycling on and off all night long as if a faucet was left open. I invested hours trying to bring my 5900 back to life then I discovered something. Something I thought anyone with one of these pumps might like to know...

The pressure switch on the “Surflo 5900 Extreme 5.7” is adjustable... Who knew!

I have not seen this shown anywhere in Tech sheets and when I called Shurflo Tech Support no one even suggested I try adjusting the pressure switch.

The center screw on the front panel (pressure switch) can be used to adjust the pressure needed to activate the switch. There are four screws that hold the pressure switch to the pump; the center screw appears to be doing the same but in fact it adjusts the position of the switch, changing the necessary water pressure to activate it.

Backing the center screw out slightly counterclockwise, reduces the amount of water pressure necessary to trigger the switch and the pump shuts down sooner. If more pressure is needed, tighten the screw. This will cause the pump to run longer and create more water pressure before shutting down. If you tighten the screw too tight, the pump will run continuously. You don’t want that and so backing it off slightly will allow the pump to cycle and shut down.

By experimentation, you should be able to find your sweet spot, enough pressure but not so much that the pump cycles continuously.

Hope this is helpful for those of you frustrated with your Shurflo variable speed pumps and thinking about replacement.

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[Ray,IN]

Individually we all need help at some point, together this community has or can find, practically every answer to a question or problem.
Thanks for posting your solution.