You can turn off the heat completley only by adjusting the temperature selector to (16°C - 60°F) and rolling the vent temperature thumbwheels to full cool. If you are still getting hot air then the control valves or controls are at fault. I had to strip down, clean and re-build the heater valves on my E34. The rubber diaphragms had disintegrated and the debris fouled the movement of the valves allowing hot coolant into the heater box contantly.
In the
diagram hoses 6 & 7 deliver hot coolant into the drivers & passengers heater boxes and hose 5 is the common return to the system. If 6 or 7 remain hot when the temp is set to full cool then it indicates the valve is passing. If you can also hear the valve "clicking/pulsing" then it indicates the valve is still receiving an opening signal from the control unit. Check that the cabin temp sensor is not fouled with dust. This is located behind the small grille on the ac control panel - see page 107 in
the manual item 17.
Note - you can still have warm air with ac on - this de-humidifies the air where the air is first cooled below dewpoint (the air moisture condensates and is removed by the ac evaporator) and then the dry air is re-heated to a comfortable temperature.
__________________
Cheers, Brian
=========================================
2001 X5 4.4i Sport
Black Sapphire, Hi Gloss Shadowline, Full Privacy Glass.
Too Cool for Jack Bauer
