Best Replacement for a Dometic 300 Toilet

Updated 06/20/2025 | Published 06/17/2025

Question:

We have a Dometic 300 and need to replace it. Do they make a ceramic 300 with a self closing lid? Also, what higher numbered series would fit the same anchor holes, etc as a 300?

asked by: Renee

Dometic 300
(click to enlarge)

Expert Reply:

Hey Renee, thanks for the picture. There are no ceramic Dometic 300 toilets, just polypropylene like item # DOM64FR.

If you have the extra 1-1/2" of space, the best option to replace a Dometic 300 toilet is with the Dometic 310 Part-Timer RV Toilet item # DOM57FR. The 300 only requires a rough in of 8-1/2" while the Dometic 310 Toilet item # DOM57FR needs a 10" rough in measurement. You will need to measure the distance from the wall behind your toilet to the center of the toilet flange. It has the same two bolt installation.

The Dometic 310 item # DOM57FR is a ceramic bowl toilet with a slow-close lid that won't slam against the rim. It is a standard height and has a round bowl. The water hook up and push pedal are on the same side.

What kind of RV or trailer do you have?

expert reply by: Jerred H