[marcosdumay]

Yes it's safety related. Turning the heater on while the airflow if off is a sure way to start a fire.

It could be fixed with a relay or a solid state switch on the heater, or with a multipolar toggle on the airspeed. But that's several cents more expensive than making it turn on at the heater switch.

[altern8]

I'm not following, that's exactly what I want, I want the fan control to also turn off/on, so fan at 0 = off, fan > 0 = on.