My son has a 2018 travel trailer with a Dometic model 300 toilet and it stinks. He has tried everything with the vent and made sure there is water in the bowl but nothing seems to help. Last night he removed the toilet and noticed there was a buildup of stuff around some seals. He cleaned it up and put some silicon around what he said was to different sections. He is camping this weekend so I did a quick search and that there is a known problem with the model 300 and I found one post that indicated a possible recall. I see they make a model 310 and a 320 with a porcelain bowl. He will call Dometic next week and see what they say. Anyone else know anything about these stinking toilets?
Have him remove the toilet but do not tilt it while it is inside the trailer. Take it outside and tip it backwards. A large amount of very smelly liquid will probably pour out.
Then contact Dometic with the serial number and they will send a replacement free of charge. I know all this because I tilted it in the trailer...
This is a known problem and they were replacing models in certain serial numbers. That program has "OFFICIALLY" ended but the problem still happens. I replaced mine through Dometic about a year ago. They offered me to either get the replacement or upgrade to the 310 with soft close lid for $75. I got the upgrade. Some people are reporting that Dometic has stopped offering but others have gotten the replacement or upgrade, Talk to customer service and be courteous and you maybe one of the ones to be offered the replacement or upgrade. You will need the serial number. Good Luck
Yes, he did just exactly that a few months ago and it was fine. He made sure there was water in the bowl to help the seal. This is a different issue with waste going around a seal. I haven’t seen the toilet but it sounds like it is a two piece one and the upper seal is not working.
I would check to make sure the vent stack isn't pushed too far down into the tank or that the roof cap on it is installed correctly with a gap at the top so it can work.