Fresh water pump will not shut off.

[Voyager Bob]

2018 catalina 355
Jabsco VFLO 5.0 fresh water pump does not shut off.  No water drips or leaks.  Any suggestions?

[Fred Koehlmann]

Hi Bob,

This can happen when the gasket between the pump and the pressurized line is not fully sealed. that gasket/valve can slowly leak water back into the pump and then the pressurized side loses pressure. At some point, the pump starts up again. How old is that pump? You might just need a "Valves Kit", to replace the valve. There is also a Diaphragm Kit if it's more serious. It has to leak past the value first, and then back through the diaphragm. So if it's old enough you may need to replace both.

[KWKloeber]

Bob

There is a potable water pump troubleshooting guide on the TechWiki.
Could be a bad pressure switch if it doesn't shut off at all. I presume it's primed and pumping ok?

[Stu Jackson]

Ken's right, discussed here.  https://c34.org/bbs/index.php/topic,10311.0.html  Different pump, same deal.

I also recall the C355 group having MAJOR problems with, perhaps, that Jabsco pump.  It came OEM and was really poor.  You can look it up on the C355 Google Group.

[Ron Hill]

Bob : With NO leaks the problem is internal to the pump!  My guess (had the same problem with my pump) was that some junk from the tank (shavings) went thru the course filter screen and screwed up the internal pressure differential inside the pump.
I called the company and told them about the problem and they sent me a new pump (as long as the old pump motor worked - which it did). 
Then I got a finer screen for the fresh water filter - Wrote that up in the Mainsheet tech notes. All is well!!

A few thoughts