Toilet waste (liquid) exiting out the air vent

[Ozark Carver]

1984 3207 Aft Cabin has always had good working toilets until this last couple weeks
All at once when the toilets are flushed no fresh water enters the toilet and the (liquid) exits the boat on the port side
from what I think is the vent tube??
At the same time no fresh water enters the boat when on shore water.---and that's only when hooked up to shore water.
We almost never turn on the water pump nor use the holding tank and up until this recent even had no problem dry
flushing the toilets while under way as we never have put any solids in the toilets at all in the 5 yrs we've owned the boat.
Can anyone see anything obvious in whats happening?
Is it that the toilets only pull fresh water from the holding tanks regardless of being hooked up to shore water?
Tight quarters down there and would love some ideas before I go down and get myself jambed down in there !!

[Tireless]

I had a 1986 Carver 3207 and the water to flush toilets came from the lake, not the fresh water tanks. Check to see if the sea cox is open or there is a blockage. Is it a hand pump toilet?

When stuff comes out the vent thru hull fitting, that usually means it is full and needs to be pumped out. If that is the case, it needs to be flushed out and cleaned. First check to see if there is a vent line charcoal filter, in that case it needs to be removed before the flush out. If filter has exposed to stuff or water it will need to be replaced.

Do you get shore water to your taps and other fixtures?

[Midnightsun]

Agreed, coming out the vent means tank is over full, needs to be pumped out ASAP. You will also need to address the vent and filter if you have one.

[Ozark Carver]

I will recheck the tank as it was pumped out recently but I never confirmed the pump out was completed.
That seems embarrassingly simple and makes total sense. Thank you for the replies and I will confirm this weekend !!
I appreciate it !

[Cooler]

If you have an electric head, Raritan brand, your flush water source is most likely your holding tank. Raritan recommended that type of installation to discourage seaweed from entering the intake and clogging up the macerator. You will need at least some water in your holding tank to flush, fresh water from dock will not go to water holding tank. You absolutely need a pump out. er

[Cooler]

What may have happened is, the last pump out you did, the person pumped out the water tank instead of the waste tank. That's why, all of a sudden you have no water in the holding tank, but your head is still full. The two caps are near each other. er

[km1125]

Source of the post What may have happened is, the last pump out you did, the person pumped out the water tank instead of the waste tank. That's why, all of a sudden you have no water in the holding tank, but your head is still full. The two caps are near each other. er

OMG, if that's the case I would bleach out the potable water system. Can't imagine what might have been on the hose adapter that was screwed into the wrong cap! I never thought about that possibility, but it makes me glad that on my boat the pumpouts are on the port side and the potable water fill is on the starboard side!

[Cooler]

Yea, I know what you mean. It depends on what the facility uses as pump out connections. Some do not have connectors, just a flexible end nozzle piece. Those are the types that dock hands hate because they can spray icky stuff all over. I did have this error happen when I pumped out once, but it was a dock hand in training. He said the discharge was completely clear, which got my attention that he pumped water, and the connector was also a different size. So no common connector with the waste flange. My caps are also separated by port and starboard location, but right at the bow, so they are only about a foot apart. er

[bud37]

One way to help stop that sort of thing is to make sure all your tank caps have their chains attached except for the waste and paint the background of the cap label black, makes it stand out.

[Ozark Carver]

Thanks to everyone - mystery has been solved
All theories were correct in some degree or another.
The sea-cocs were never opened from summarization, as the boat was under gen set removal and replacement over the summer and was overlooked... thus no water was being introduced to the flush system.
The last pump out was not successful back on July as I find out the marina pump out system was not working well.
End result was as described by everyone and 100+% full waste tanks and it just a case of me not even considering they
had not been emptied when I last had the pump out done.
The toilets had been back flushing out the vent as there was just no where else for it to go.
Fortunately the boat's use was very low this summer and had very low toilet use.

All in all things seem to be doing as they should now.
Thanks again for the helpful advise and I am glad I joined this club for sure !!!
(Next is the gen-set continuation of problems which I see are talked about a lot on this site)
Best to all and thanks again !
-Ozark