FW pump cycles occasionally but no leaks found?

[SV Demeter]

Could this be the pressure switch starting to go? I've had a pretty good look over the system and have not found any leaks but every so often the pump cycles for about a second. Should I look harder?

[Sailmonkey]

I had the same thing from mineral build up on the internal check valve in the pump. The cure was to disassemble and clean.

[Khagan1227]

Generally a cycling pump indicates a system leak.

Put tissue over the drains of your shower and sink. If it ain't there, time to get out the flashlight and go bilge diving.

[SV Demeter]

Like I said I've already looked all over for leaks. We live aboard. Guessing I should take apart and clean the pressure switch.

[Sailmonkey]

I really doubt it's the pressure switch, it is responding to a drop in pressure and cycling the pump on to build pressure back up.
The pump relies on one or several internal check valves to build pressure downstream of it and keep the pressure down stream. when these are either crusted with minerals or have a small something in them they leak slowly causing the pressure switch to close and cycle the pump on.

[Jim Cate]

Originally Posted by Sailmonkey

I really doubt it's the pressure switch, it is responding to a drop in pressure and cycling the pump on to build pressure back up.
The pump relies on one or several internal check valves to build pressure downstream of it and keep the pressure down stream. when these are either crusted with minerals or have a small something in them they leak slowly causing the pressure switch to close and cycle the pump on.

I agree that this is a very likely cause for your symptoms.

Cheers,

Jim

[sailorboy1]

normal, do nothng!

[Jim Cate]

Originally Posted by Don L

normal, do nothng!

Not normal on any of my boats, Don...

Jim

[Sailmonkey]

Originally Posted by Don L

normal, do nothng!

I can leave the pressure water pump on for weeks and it wont' run unless I open a faucet.
I did have this problem in Guatemala when we were filling the tank with liquefied rocks from a well.

[sailorboy1]

far as I'm concerned the pump running once in while is normal, on mine it takes hours if I'm not using the water

I have better more useful things to take apart to 'fix" than to screw around with the FW pump to clean the check valves to stop it from running once every few hours.

Ted do you have an expansion tank in the system? If not only a little water will drop the pressure and the pump will start more often (sounds like you don't if it only takes a second to repressurize the system).

PS - I have never been on my boat for weeks with the pump breaker shut without using any water, so I can not say if the pump doesn't run for weeks.

[Sailmonkey]

Originally Posted by Don L

PS - I have never been on my boat for weeks with the pump breaker shut without using any water, so I can not say if the pump doesn't run for weeks.

Ok, it's purely conjecture on my part, extrapolated from the available data set at hand, that my pump can sit weeks without running. Perhaps I may have taken literary license with the true time frame in question