On the Azi, the sink units and showers from both heads run into a collector tank, and then the waste is pumped out by a Whale Gulper 220. There is a solid state sender unit which triggers the pump on and off. It looks like this has failed, as the full warning light came on at the weekend, and I had to manually switch the Gulper on to drain the tank. Any thoughts on the sender unit manufacturer and type? Not being lazy, but will not be back on board for a couple of weeks.