Originally Posted by rjtrane
3. The VF has a 3/4" orifice at the toilet valve. The remainder of the circuit is 1-1/2". Thus, the clogging I've seen is ALWAYS at the valve in the toilet.
4. Using the screw driver, force the clog through the 3/4" orifice.
5. The vacuum should suck the waste to the tank
Worked like a charm !! My stuck master cabin head is working again. Trip-saving advice from rjtrane !!
Also, in my boat, there is a manual activation switch on the Vacu-Flush circuit (so it doesn't randomly start up at night when the vacuum pressure drifts down and wake us up). There is a 25 amp fuse protecting the circuit. On one occasion, after a plugged toilet (at the 3/4" orifice) the fuse blew. After manually clearing the orifice, there was no suction and no pump action when flipping the manual switch. I removed the cover on the vacuum container (below decks) to expose the wiring and put my voltmeter on the supply wires, only to find no power (zero voltage). I visually traced the wires back to the electrical closet and found a fuse. After replacing the fuse, the pump and vacuum were back on.
For fire safety, every circuit should be protected by a breaker or fuse, so if the vacuum pump will not run, check the 12V supply.