There is a switch on the side of the proheat to turn it from floor to tools, this operates a small lever/paddle that you should be able to see moving - is this working? If not you need to replace it, otherwise a kink in the hose is the only thing I can suggest.
Chay
October 2009
I can answer this question...
How can I get the rug shampooer to suck up the water on the stairs?