Harry, that control allows coolant to circulate through the heater core.  Summer, off, winter, on.  To control air flow, use the knob on the dash.  mcneely

---- Harry Hoffman <hhoffman@IP-SOLUTIONS.NET> wrote:
> Hi all,
The heater under the rear seat has a control knob.
Can someone tell me what it does? The Bentley only shows a picture but not how it functions.

 Cheers,
Harry

--
David McNeely