Freshwater pressure switch sticking

[nuru05]

My freshwater pump is acting up. The pressure switch seems to be sticking in the off position. I pulled it apart and played with it and it worked for like 10 minutes but then I went to use the water an hour later and it doesn't work again. Do I need to lubricate it or something?

[thesaltytar]

This is hard to diagnose without more data points.

It could be the switch going bad, it could be the pump (switches tend to fail first). Another consideration is maybe an electrical connector either has failed or is failing - test all the butt connectors and inspect the wiring. Maybe a connection got wet and corroded.

See if you can get it working properly by jiggling each thing in turn (tapping the pump, tugging the wires, tapping the float switch).

Multimeters are really good for this sort of thing and I always have one handy. It will save you SO much time trying to properly diagnose these issues. I prefer Fluke but anything will do the job.

[thesaltytar]

Sorry I reread that and see it's a pressure switch. Same logic still applies. Double check the pressure really is what it's supposed to be and basically trace out the voltage step by step.

[nuru05]

Originally Posted by thesaltytar

Sorry I reread that and see it's a pressure switch. Same logic still applies. Double check the pressure really is what it's supposed to be and basically trace out the voltage step by step.

if I pull the pressure switch off and press on it with my finger it works like it should and the pump fires on and off just fine. Then when I reinstall it the pump works initially and shuts off when it should but if I go to try and turn water on a few minutes later it doesn't work. I've repeated this process a couple of times.

[thesaltytar]

Let me make sure I'm picturing the right thing. Is this what we're talking about?

https://www.pumpproducts.com/blog/ho...e-switch-work/

I'm interpreting what you say as that when you open the housing up and press on the contactor, the pump operates. This confirms the electricity, the pump, and the wiring.

Next question is what pressure the pump stops at? I'm assuming you have a gauge on the system and one of the gauges should be able to tell you what the pressure is where the pressure switch is installed; if not this would be good information.

I'm wondering if one of the adjustment screws got turned out by mistake and perhaps this is just a setpoint issue?

[Lepke]

It would help to know the pump make and model.

If it's a typical pump with the switch in front, most pump makers use a micro switch that's not rated for 12v dc, but for 125vdc at less than 1 amp. What happens at higher amps is the contacts get burned and pitted and eventually either stick together or fail to make contact.

A common pump micro switch shown. You can buy them on Amazon or ebay for less than $10.

[Bowdrie]

You don't indicate your location.
Most any "big box" store or Ace Hardware will have a Square D pressure switch, (commonly used for well pumps).
They come pre-set for cut-in ~20, cut-out ~40psi., and run ~$25>$30.
Furnas makes a better quality one for a few bucks more.
Or, the local auto parts store will have the "little black cube" Bosch relays.
The Bosch hook-up is a simpler job, (no hook-up into water line,) but it still depends upon the original switch, and as such it's not the best solution.
Do you have an accumulator tank?
The use of an external pressure switch and accumulator tank will eliminate most of the problems with a water system.
PS., Having pump inlet in a flooded condition, (below tank level,) highly recommended, pumps do MUCH better when pushing water than when sucking water.