Here's a hack that might be helpful to others.
Problem: flush volume is fixed at 1.2litres. For many systems this does not leave the pipes with clear
salt water, and the mix of urine causes calcium build up.
Solution: by
wiring a pair of manual switches to the
control box the fill
pump and flush macerator can be controlled manually.
Here's a pic of the
wiring to the control side of the relays on the circuit board.
At the other end of this wire a switch connecting blue to yellow or green activates the
pump to fill, and connecting red to yellow or green activates the macerator flush.
I suggest using a
single pole double throw switch to do both so you can only activate one at a time, as the unit wasn't designed to do both simultaneously. Also dead man's type switch prevents it accidentally being left on and flooding.
If anyone can figure out how to adjust the timing circuit on the board so it runs for longer please post the suggestions. I suspect the time is programmed into the chip. Thanks.