On my 35-3 the sink drain and the flush water pick-up tee onto the thru hull valve. It may be necessary to put the sink drain stopper in to pick up flush water when drawing water from overboard. 1 leave the thru valve closed. 2 run water into the sink. 3 Now I flush the head. This will draw the...
I own a 35-3. I removed the outer cover, pipe fittings and insulation. The tank came out through cockpit hatch then.
I replaced the Raritan with a 5 gallon Isotemp. The Isotemp is heated from the engine or 110v A.C. It has proven to be a great unit.