is an excellent toilet. There's no way to "convert" a fresh water to toilet to sea water (or a sea water toilet to fresh water) because the only plumbing
they have in common is the discharge hose. Toilets that use fresh water don't have an intake pump, sea water toilets do. So you'd just remove the Jabsco
completely and install a complete Lavac.
However, there are other toilets that also use pressurized flush water that are worth considering: You can upgrade your Jabsco electric to the fresh water version of a Raritan
SeaEra by replacing only the "lower unit" (everything below the bowl SeaEra Conversion Kit
. Depending on which model Jabsco you have, the mounting bolt patterns may even be a match for it. Or, if you're determined to convert to a manual toilet, the Raritan
Fresh Head Raritan Fresh Head
is the only MANUAL toilet designed to be connected to the onboard potable water supply. Both are TOP rated by Practical Sailor.