Need Help With Head

[SVNeko]

I had a Jabsco manual head that would sometimes lock up on discharge. Sometimes it would operate properly and sometimes it would just sit there and not empty while I pumped and pumped. There was no extraordinary pressure on the pump and it is not a blocked discharge or tank vent, I checked those first. This is the guest head and the intermittent operation was very embarrassing. So I changed the manual pump out for the Jabsco electric conversion and, guess what, same issue. Sometimes it pumps out and sometimes it doesn't. It seems to me like some kind of airlock or loss of prime but I can't figure out why. It draws water fine and the discharge is plumbed from the pump down about 6 inches and then up to the tank about 4' above the bowl.

Any ideas anyone? Please no recommendations for switching it out. It should work and I just want to figure out why.

[SVNeko]

Bump. No help out there?

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[ColdEH]

I have just about the same problem with my guest head , I'm sure it is the hose's that are blocked from the outbound side . I'm just going to replace it with a freshwater setup as I did with my aft head .
Have you replaced the hose from the head to the tank ? If you are using seawater , calcium always builds up slowly and narrows the hose .

Regards


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[SVNeko]

Yea, replaced the hose a couple years ago. First thing I checked was clogged discharge and vent clog. So here's the answer: Called Jabsco in the UK and got a quick tip. I had left the vented loop between the pump and the head. The electric conversion unit comes with a small hose to replace the vented loop and go straight from the pump to the bowl. The instructions were vague and suggested leaving the vented loop in, and I did that. The guy from Jabsco UK said to remove that and put the small hose in. I did and it worked. Even though that hose is for the intake, there is a small bleed hose between it and the discharge and I think that was allowing air into the discharge pump. So, for what it's worth for anyone else with this beast, there's a tip for ya.

[peghall]

If your toilet is below the waterline, even only when heeled, the UK Jabsco rep gave you bad--or at best, incomplete, advice... because without the vented loop, there's nothing to prevent water from entering the bowl on its own. He should have told you that a solenoid valve (Jabsco part # 37068-2000) wired to the flush button is needed to replace the air valve in vented loops on electric toilets. The loop does need to be moved to the line between the thru-hull and the pump...the solenoid closes the the air valve when the toilet is flushed, opens it when flushing ceases to break the siphon.

See it here on the Jabsco (now owned by Xylem) site:
37068-2000 Vented Loop Solenoid Valve

[cabo_sailor]

Peggie,

What would this forum be without you? So many of us owe you so much.

Thank you,
Rich

[SVNeko]

A Switch 51 is a catamaran. If the head is ever below the waterline, I have bigger problems than that. But where were you when I needed the help in the first place?