Guys thanks for the encouraging and positive response. A true community. I'll go and try the heater controls and see if I can shut it down. I think I've currently 3 clicks so there's another one or two in there. We're off to the continent in June so I really need the fan to turn off.
Mark. The fan has only 3 positions: Off, low, and high. The heater control is the knob with a sort of wave on it, on the LHD car it is on the right but I think it is the same on RHD cars. When it is off the symbol is horizontal.
Down under the dash in front of the brake lever there are two vents which can be adjust for opening and angle of air flow. They are aimed towards the seats. On either side of those, at the side of the footwell, there are another two vents aimed towards the sides of the car. These can also be closed or have the direction of airflow changed.
Hope this helps