I have a Lennox 80MGF3/4-100A-1 furnace. According to the stickers it was converted to a heatcraft ignition control board EGC-1 at some point. I just moved into the house and noticed that I can not kick on the blower manually. The Heat and A/C both work fine and it kicks on automatically when needed. However, I'd like to be able to set the fan to ON to circulate air without heating/cooling.

I thought it might be a loose wire on the thermostat, but everything appeared connected. So I purchased a new thermostat thinking maybe that was the issue. That did not help. I'm assuming this has to be a wiring issue, but know nothing about HVAC. I took pictures of everything that I thought was relevant in case that helps. Does anyone have suggestions for what I can try or what would be the cause of this?

Pics can be found here:
Https://picasaweb.google.com/107022855886113072599/FurnaceBlower

Are you sure there's a green wire connected to G post on the tstat

It sound like you have a problem on thermostat a wiring from the furnace to the thermostat

Please email me at [email protected] if anyone has a solution to this problem.

Thank you!