Black water flush

[Mgeist]

When we attach hose to black water flush and other end to water source, open drain and turn on the water, no water comes out the sewer pipe.

[mikew968]

Stupid question but are you opening the black tank valve? Do you have water spraying onto the tank? You can hear mine spraying the inside of the tank and yes after a minor two water does start coming out.

[Mgeist]

Thanks, yes the black water valve was open. We tried it again and it did work. Guess we didn't wait long enough ( there was a line of Eva waiting).

[wags999]

Sounds like your black washers are either clogged, or, the internal back pressure valve is not operating. You should hear the water running inside the tank when on. Do you use the washer each time you dump? Has it worked in the past?

Good Luck.

[Mgeist]

Thank you for your help. We think it is working now.

[Bluesky46]

When I rinse the black tank, after the initial dump, and after dumping the gray water. I close both valves and turn on the rinse water being careful not to let it overflow. I usually fill the black tank 1/2 or more full, then dump it all at once. And as already said, I can hear the water running into the tank.

[Skaling]

The back flow valves are notorious for leaking whilst in use. When I am flushing my tank I place water absorbing towels under the valve just in case and I am always running back and forth between my control panel, the bathroom sink area(where my back flow valve is) and outside the trailer, always looking and listening to make sure everything is going well..

[Paulg1940]

Originally Posted by Bluesky46

When I rinse the black tank, after the initial dump, and after dumping the gray water. I close both valves and turn on the rinse water being careful not to let it overflow. I usually fill the black tank 1/2 or more full, then dump it all at once. And as already said, I can hear the water running into the tank.

The rinse water is not entering the tank. That is the problem. Could I stick a hose down the toilet to maybe unclog it? What if I tried to rinse from the outside at the same to,e o flushed via the toilet? Will I break or damage the tank?
Thanks

[WaltW]

Before black tank flushes were installed by the manufacturer the only way to clean the tank was to insert a wand into the toady and turn the water on. There was nothing in the way to be damaged. Suspect it is the same now. The problem may be that whatever is plugging it up cannot be dislodged by water pressure from inside. You might need to get one of those thingeys that shoots water in from the valve to dislodge the blockage.