Catalina 350 International Association

I have noticed that if we don't close the fresh water intake valve...the head fills with water overnight. Has anyone found a resolution to this problem?

Is the water clear that you're seeing? I can't figure out any way that water could enter the bowl without activating the pump.
I suspect that the joker valve is failing. When you pump waste into the holding tank, the joker valve keeps material that is between the discharge of the head and the intake of the tank from flowing back into the bowl. I replaced mine last year and it wasn't too difficult.

Had a similar issue this weekend. Not sure what a joker valve is but on my siphon loop the small valve at the top was not opening to let air into the hose from my "A" valve (sea water) to the head, therefore it siphoned the water in the hose back into the head. Take the valve at the top of your siphon loop apart, clean it with fresh water and squeeze it to make sure it opens and closes. Put it back together. This solved my issue.

Let us know what happens after you clean/replace the anti-siphon valve on the head intake.

Is it located high enough that it does indeed "break" the siphon.

Brett Wolfe
350 #180

Yes, the water is clear (fresh water), I replaced the Joker Valve & both Impellers last weekend but the fresh water is still coming in. If I close the through-hull, no water comes in so it must be the vent fitting?