Black tank flush (1995 Sovereign)

[jornvango]

When we hook up a water hose to our black tank flush and open the black tank dump, nothing comes out.

The Airstream manual explains that a 'valve' has to be opened, I assume to let the water pass from the black tank flush hookup into the black tank.
Does someone know what this valve looks like and where I can find this? I assume it's somewhere in the bathroom or vanity area.

Thanks.

[cwf]

It is possible insects have clogged the inlet. Can you look into the flush hose connection with a mirror?

The valve is the waste valve.

[jornvango]

The manual differentiates a check valve and a gate valve.
I assume the gate valve is the sewage valve, operated when dumping the black tank contents.

See attached picture.

Where is the check valve and goes one usually leave that opened?

[cwf]

Originally Posted by jornvango

The manual differentiates a check valve and a gate valve.
I assume the gate valve is the sewage valve, operated when dumping the black tank contents.

See attached picture.

Where is the check valve and goes one usually leave that opened?

The check valve is automatic, usually internally spring loaded. Water pressure overrides the spring pressure letting water flow.

The Vacuum break is also to be checked. It's purpose is to ensure water drains from lines so there is no water there during freezing temps.

Last, the nozzle itself may be clogged.

These parts are accessed from underneath the AS. You need an access panel to service them.

On out 1999 Excella it looks like this