Jabsco head seepage back into bowl from holding tank

[Peggie Hall HeadMistress]

Yes, the discharge from the toilet goes vertically about four feet then into the top of the tank at a right angle fitting. Wouldn’t pumping in the dry mode just send air bubbles up through the waste in the 1-1/2” hose, especially if it is mostly liquid waste? Thanks!

Nope. The dry mode can move bowl contents up to 6 level feet before it breaks up into bubbles. Your toilet can lift up to 4' in either mode, so it should be able to get the flush all the way into the tank in the dry mode, leaving no more than about a cupful in the hose to run back to the toilet....which is why you should always follow every flush in either mode with a wet flush of at least a pint of CLEAN water to rinse out the discharge hose, switching to the dry mode to move that water into the tank, leaving only about a cupful of clean water to run back to the toilet.

--Peggie