Thetford Cassette toilet - he-ruide
Q. The fresh water tube is full, does that mean that the fresh water tank is full?

A. Not necessarily.  The fill tube is "U" shaped.  The way to know if the tank is to look at the sight tube shown in the next photograph.

Q. The fresh water tube is full, does that mean that the fresh water tank is full?

A. Not necessarily. The fill tube is "U" shaped. The way to know if the tank is to look at the sight tube shown in the next photograph.