Black Tank Backflush plugged at tank connection

Factory flush spray nozzles can be glued to tank OR they can be spun at high speed which melts plastic and 'welds' them to tank

When holes in spray nozzle get clogged (usually from hard water minerals drying out inside nozzle) they are virtually useless.
Now that you have hose cut off you could try filling hose with CLR and let it sit/soak




If it is an aftermarket kit then spray nozzle will be installed using screws/sealant
If you can't get to it to remove.....abandon in place and install new

Seems to me that there is a check valve (backflow preventer...anti siphon) located just inside the connection. It's usually cheap plastic and get hung up easily. I had mine replaced early on. One has to get to it from the outside by cutting away the sealant and removing the inlet plate.

Moved from Forum Technical Support

mine has an anti siphon valve located under the bathroom sink.

i would check that before going any further.

The answer depends on the flusher.

Model: The Flusher: (yes that's a model) is nothing more than a sprinkler head, the backflow device is "up-line" from it and is a vacuum breaker that is mounted ASBOVE the top of the tank.

Model: Tornado: Has a spring check vlave in the flush head itself.

others: Vary.

Recommendation: You must likely have one like "The Flusher" from the factory, Replace with Tornado, i did.

Recommendation 2: I feed the Tornado via the original vacuum breaker, PLUS a 2nd Spring check and vacuum breaker on the supply hose.. Belt and Suspenders. 2 sets. Am I paranoid.... Well when I "Bult" the hose I did not knwo about the existing back flow preventers so no. Not that much.

Oh, and I use a Quick Disconnect so when not flushing, Hose is disconnected (At the moment it is connected to a hand sprayer).