Greetings all. So we just took ownership of a new-to-us 2003 36mkii. While I have a few questions for which I may lean on this community, one that is most pressing is that of our holding tank swelling.
While we weren't present for launching, we were able to get out to the boat after a couple days for a shakedown. Noticed almost immediately that the head became difficult to flush and got some backflow. At first I thought maybe joker valve as there were no bubbles indicating a possible blocked vent.
After a few more flushes throughout the day, I noticed the tank began to swell significantly. I had initially ruled out a full tank as it has been pumped out for Winterization when hauled in the fall, and not used since. Also, I would think if full, I'd see some waste coming up the vent line, but upon inspection at the elbow, it looked clear. Is it possible it could be blocked at the stanchion? Any easy way to check? Not sure what the easiest access might be.
Another thought I had was that when the yard launched, they left all seacocks open...to include the macerator thru-hull. I immediately exercised it and closed it. Is it possible by sitting for a few days open the tank could fill with seawater? It's been sitting idle on the mooring...no starboard tacks. Also, I would think a filled tank would still push up through the stanchion.
I'll go ahead and pump out ASAP but curious about your thoughts? I found a few similar threads on this but most seem to go back a few years. Thanks in advance for any help you could provide!