We had a Thetford Aqua Magic in our 5th wheel and at times the water valve wouldn’t shut off after flushing, it would fill the toilet then run slowly until it over flowed on the floor. Not saying the Thetford’s are bad just relaying what we had going on with ours. If you read the reviews a few other folks have had that issue too. We didn’t want to mess with changing the water valve any more (3 times) so we just pulled it out and put in a new
Dometic 320 with the sprayer for cleaning. Two nuts to remove at the base and a water line to unhook. A little floor cleanup and drop the bolts in and tighten it down. Then hook up the water line and its a done deal. DW and I are in our mid 60’s and have health issue, so we won’t take on anything too tough. It took us maybe 2 hours to do the whole thing. Go out to you tube and you can see what’s involved its a pretty easy fix if you decide to replace it.