For clarification - the toilet is a not the problem - the 1/2 bath has its own black tank. To dump the tank - we have to open a valve (just like the valve on a grey water or black tank) then the material goes from a 4" to a 2" (roughly) pipe that is directly connected to the macerator. From the macerator there is a 1 1/2" hose that runs to the other side of the RV where another valve needs to be open to empty the tanks. Once both of these valves are open - we press a button to turn on the macerator pump - and if working correctly - it will essentially 'blend' the material and the 'vacuum' will pump it out to the side where it can be dumped. Right now - we open both valves and turn on the pump (the pump runs) but nothing really comes out.