Master bedroom bathroom toilet/ black tank not draining. Wet vacuum suck out and removed waste, 1/2 gallon of septic chemicals with boiling hot water

[Biggboyz1]

Please help, any suggestions...
Master bedroom toilet/ black tank not draining, tried everything...multiple times...

 

[cookie]

Have you checked that the drain valve is opening when you pull the handle?

Peace
Dave

 

[travelin2]

Do you have one of these to see what is or isn’t draining? It’s also a back flushing valve

 

[david-steph2018]

Please help, any suggestions...
Master bedroom toilet/ black tank not draining, tried everything...multiple times...

Just to be asking, you do keep the drain valve closed until it is time to dump, correct?

 

[Routemaster]

Just maybe you have the scrap slug that they drilled to fit the down pipe floating down to the valve just like I had in our old Everest?