I have an American Standard variable speed gas furnace, with a variable speed draft inducer. (AUY060, also the same as a TUY060). Whenever the inducer is running, there is a lot of radio interference generated. The interference exists before the blower fan turns on and stops immediately at the end of the cycle before the blower fan turns off. When the draft inducer fan speed increases, the interference pitch increases too.
Someone told me that this is a known problem for Trane/American Standard. Last year, my professional HVAC company obtained a new main board from the distributor and replaced it under warranty. However the noise is unchanged and can even be heard on a radio outside of the house.
Has anyone heard of this problem or know if it is really fixable? The manufacturer won't say anything and directs all calls to the regional distributor, who is the one who said to replace the main board.