If by chance your new RV came with a Dometic Series 300 commode as standard equipment and suddenly your bathroom smells like a cesspool, here’s what might have happened. Unlike commodes in the past, the top and bottom halves of this appliance are sealed internally and are not to be separated. Do not attempt to separate them!
All goes well unless the seal breaks, and the rear of the commode becomes a storage container for bodily waste. When this happens the entire commode must be replaced. The Series 300 has been replaced by Series 310 at your service center.
If you choose to replace it yourself, shut off the water to your RV. Disconnect the water line at the rear of the commode. Unbolt the commode from the floor and lift it straight up. Do not tip it or turn it upside down or you will have an incredible mess. There are no parts from the old commode that will be reused on the replacement.
Editor’s note: Several RVers have commented about this problem; all have reported that Dometic was quick to respond by sending out a new 310 model toilet.