Don't feel bad I replaced my old Jabsco
in the V-berth because it would not work after the third time it was rebuilt (many things flushed with kids) Installed it could not get raw water
to do any thing but trickle IF THAT. Spent two days off and on going through what could be the problem and finally resorted to using the fresh water shower
to fill and flush. Any way there was nobody using the fwd head
very often and let it be... Finialy I installed a ele. head
and was having the same problem## did I mention that the first replacement had gotten a new raw water
sani line. After having someone pressurize the line I find a pin hole that would not leak but would suck air... YES I did feel like an idiot for not checking the new hose!!!