1984 Catalina 30 Pumpout Question

[alucas100]

OK, the vent on the stanchion was sealed with electric tape, I can´t believe I did not notice that before. There is no other inlet going to the toilet other than the seawater. So if the holding tank was not vented, this might explain how the freshwater tank was sucked out first. Only after the starboard tank was empty and allowed air into the system was a siphon possible to begin and to empty the holding tank. The powerful vacuum gave the freshwater enough momentum to jump the high loop under the sink. This is my theory anyway, Peggie, please let me know what you think. Based on what you told me, I don´t think the freshwater is actually tied into the wastewater system at all. The other day when I pumped the toilet with the seacock closed and water came out, it was what was left in the raw water inlet line.

[alucas100]

BTW, I was on the right fitting, please refer to post #3, see ¨brown¨. Water tanks are starboard, fuel, power, and waste are port. But seeing clear water come out first, then all the waste one right after another was a shocking scenario. I think I got it, but waiting to hear back from Peggie Hall. Thanks all for responding!

[peghall]

The powerful vacuum gave the freshwater enough momentum to jump the high loop under the sink.


You lost me with that.



There'd be no way for a pumpout connected to the holding tank to pull water out of the water tank unless water tank plumbing is somehow connected to the holding tank and/or its plumbing.


But...we're making progress...we'll solve it.


--Peggie



--Peggie

[Frank999]

On my 1987 Catalina 30, the holding tank vent is in the base of the port lifeline stanchion that is nearest the head. I'll bet the OP's is, too. I suggest that a stream of water from a hose directed into the opening might be a good way to unclog it. The opening is on the inboard side of the stanchion base.