Heads problem - fills up to brim

[svrevelations]

We have a Jabsco electric heads which completely fills up with seawater after flushing. We would flush the heads and about 30 minutes later, it is filled to the brim. The brim is at the same height as the waterline outside. What gives? Where should I start looking for the problem?

[hummingway]

Has it done it since installation? Do you have a vented loop? Is the vent valve functioning?

With the regular heads filling can mean the bottom seal is going. I don't know if it's the same with the electric head.

[SkiprJohn]

I'm not familiar with the brand or electric but it sounds like you've got a flapper that isn't closing or you have a vented loop which is not vented properly.
There are experts here who will chime in soon.
kind regards,

[svrevelations]

There is a vented loop and the problem started a few months ago. Will check whether the anti siphon and flapper is working properly. Thank you!

[US1Fountain]

Mine will do this on occasion too. Jabsco Quiet Flush. Mine goes directly into a holding tank though. The amount of back flow I get is the same amount that happens to be the capacity in the discharge line, that passes back thru the joker valve. Luckily I'll never have an overflow since it's a holding tank and limited to the capacity of that discharge hose. I replaced the valve last week and it did it again. I'm finding the wife doesn't flush long enough to make sure there was no TP caught in the joker valve holding it open. If flushed clear, then just enough water to fill the small opening in bottom of bowl, then flushed again, it is fine.
Ordered a new higher volume fill pump to install this weekend to make sure I get a good amount of water to push all contents past the joker valve. Current pump only supplies 1 gal/min. Jabsco recommends a 3.3 gal/min pump.

[HopCar]

You didn't say so but I assume it is filling with clean water since it only fills to the water line. It would really help to know what make and model the toilet is. You said that there was a vented loop. Is the loop in the intake hose or the discharge hose? If the bowl is filling with clean water, no need to worry about the discharge side of the toilet. The problem is on the intake side. The valves in the toilet that prevent water from flowing in are bad (or you're not using them correctly) and so is the intake vented loop. If there is no intake vented loop, it sounds like you need one. It should go between the pump and the toilet bowl. If you put it before the pump, it will let air into the suction side of the pump and reduce the effectiveness of the pump. Get the book "Get Rid of Boat Odors" by Peggie Hall. It goes into the proper installation of a marine toilet in some detail. Peggie will be mad at me for not putting a link to where you can buy her book, but if you can't find it, I have them in stock.

[bobconnie]

Hopcar You crack me up LOL You really have the stuff a cruiser needs, you must be good at your job cus you sure stock the stuff thats great to have and sometimes hard to find ! Gonna have to stop in the next time Connie and I are down that way, seeing a boat or seein grand kids in Lauderdale!! Then I will get to see some of the stuff Ive only seen in books and catalogs!!

[HopCar]

Bob, Please stop by. I'd love to meet you. Maybe we could grab a bite to eat and talk marine toilets? On second thought, maybe not. We'll find something else to talk about!

[zeehag]

when my jabsco toilet fills to brim is because of one or two different things--either wasnt pumped to DRY or it was left on wet pump. good luck. mine is 10 yrs old sans rebuild. used daily many times as i am a living on board cruiser. previous owner was a live aboard.