Kiwi.
Member
I got typical small to medium boat system with an 18 gallon tank, a Y-Valve and a Macerator and of course the sea cock ball- valve deep in the bilge.
With the Sea Cock open and the Y-valve in the “Normal” position, the tank is gravity draining from full to empty in 5-6 hours.
For some reason I thought this was not normal, but looking at the schematics, there is no check valves and the macerator will let fluid drain through the impeller.
(Everything is brand new: Head, tank, valves, etc. Not an issue of build-up and old seals)
Yes it will be draining through the macerator pump. I've had identical macerator pumps, one drained the other didn't.
The big problem I had with the one that drained was when the boat sat on its dock for three months. Toilet paper makes wonderful paper mache once it's fully dried and, because the pump impeller was doing a great job of letting fluid out whilst keeping paper in, we ended up with a solid paper mache layer blocking the bottom of the tank and the pipe.