In Reply to: Heater not blowing warm air posted by Neepu on January 24, 2000 at 17:58:03:
I may be speaking out of context here as I have a 535 but check your auxiliary coolant pump for functionality.
It is situated on the left side firewall and is tucked behind and below the valve unit that regulates coolant to the heater cores. I'm going by the fact that you get heat when the engine is at higher RPM but not at idle.
The function of the pump is exactly what you desire - rapid warm-up of the heater core. It may be easier to track the pump down by following the heater hose coming off the front all the way to the back. Bentley does discuss this pump and has a photo of the valve unit I mentioned.
Good luck; stay warm,