I'm in the PNW and we're dealing with lots of wildfire smoke. Accordingly, I've been running the fan on the HVAC nearly continuously for the last 4 days so that air will go through my electronic filter attached to the system. Last night, I woke up to go to the bathroom and on my way there noticed a faint burning smell coming from the return air vents in the ceiling. I also noticed that even though my Google Nest expected the fan to still be running, it was not blowing air out of the registers.
I turned off the fan and left it off for the rest of the night. This morning, the fan (by itself) or the AC (with the fan) seems to be working correctly. What might have happened here, is it a concern, and is there anything I should do in response?