I had this furnace and an XC-15 air conditioner installed 3 years ago.
No issues until now. We leave the blower on all summer to help circulate
to our warmer 2nd floor, but I noticed it wasn't on today. It's been
cooler today, but when I turned the thermostat down low, the condenser
kicks in and then shuts off after a minute or so (I assume because it's
made to do that when the fan isn't working?).

We did have a 1 hour neighborhood power outage yesterday evening, but
I'm not sure if the fan stopped after power was restored.

Any simple things I should check before calling for service?