I am operating with a Thetford Aqua-MagicĀ® Style II. I full time and I'm on unit #4. The first three failed in various ways from the water valve, foot flush mechanism, etc. Each time warranty covered it so I'm not out any money, but I am convinced of one thing. RV toilets aren't designed for full time use. The components just won't hold up. When this one fails I'll just buy another one and chuck this one in the trash. Changing the water valve involves messing with the foot flush and vice versa and if you change one you screw up the other. IMHO
Not worth changing parts. I just wish someone would make a quality unit.