Lennox G26Q3/4-100-1 Fan non-op in Auto

I have a Lennox G26Q3/4-100-1 which recently stopped working correctly on the Heat/Auto setting. The fan simply would not come on though the burners were firing properly. The fan works properly in the On setting but not in Auto. For the last few days I've simply increased the temp setting on the tstat, turned the fan to on and then I've got heat. Obviously this is not the way to do this, I need the Auto setting to work.

From the research I've done it looks to be the fan control which (I believe) is integrated into the circuit board (BCC?). From the Lennox manual it appears the correct part is the 63K8901 or . But whenever I search for that part I get updated versions. The main one seems to be this 83M00 or somesuch for ~$200. In a couple cases I've also received results for a 48K98 which is significantly cheaper. It also cross referenced an LB model number which is the one that came up as 48K98.

Is the 48K98 a direct replacement for the 63K8901 or no? Bottom line is I don't want to buy a more expensive part if I don't need to.

Appreciate any help and comments.

Thanks.

Jack

 

The 48k98 is not correct. the correct OEM part number is 83M00. Or you can go aftermarket and get a 50M56U-843