jferre9570 wrote:
I know of at least one instance where the pipe down into the tank wasn't cut short enough; as liquid built up in the tank, solids could not free-fall into the tank. You should be able to see this condition if your connection is straight down.
This is what I suspect is your problem......
The dump line from toilet to tank is too long and sticks down inside tank very close to bottom of tank. Solids and TP are piling up regardless of amount of water used.
To correct, the dump line will need to be shorted.
Remember , waste tanks are not very deep...they are wide, long but shallow.
And yes RV toilets will 'burp'.
When they get close to being full the liquid can block the vent line. When you flush toilet air has to escape the tank in order for liquids/stuff to enter as it is a gravity operated toilet.
Hence the toilet dump line becomes the vent source and produces a 'burp' sound as you flush.
This should only occur when tank is nearly full. Happens at other levels then vent line is obstructed OR too long.