My Vax 2000 w/d vacuum won't draw the soapy water from the drum. ?

Hi there,

I have a vax model 2000 which won't draw the soapy water from the drum to the hose.

There doesn't appear to be anything wrong with the hose, I've checked for kinks and blockages. I've also tried elevating the main unit by carefully standing it on a chair.

After going through the instructions repeatedly to see if I might have missed something and can't seem to see what might be wrong, I am totally baffled!

Can anyone help please?

Thanks for looking :)