Many thanks to all contributors for your advice :-)
I have just replaced my Very Noisy Jabsco
37010 12v electric marine
toilet with a much quieter TMC 99902 12v marine
They look the same, same dimensions same layout. Fits nicely into the spot.
My holding tank
is at the end of a 7m (21 foot) 25mm reinforced hose. The base of the tank is 100mm (4") above the bottom of the toilet bowl, the tank is 450 high and the hose feeds into an elbow
at the top, giving a 600mm (2 foot) dead rise over 7m
was happy to flush and empty the bowl.
The TMC pumps water
through but takes in more water
than it can push out and eventuially fills to the top and must be bailed out.
Have I incorrectly installed the new toilet or are the TMC unable to pump the 600mm dead rise to the top of the holding talk?