Help troubleshooting why furnace won't kick on

We got home tonight and thought the house felt cool. Although the heat was set to 75, it was only 71 in the house. I cranked up the setting to 80 and went outside to see if could hear anything - nothing. I turned the AC unit on and it came on fine and was blowing cool air.



This system is about 15 years old and is a "gas pack" system. Over the past 5 years, just about every component has been replaced in this HVAC system (thankfully, we had a home warranty each time. Unfortunately, we decided not to buy one this year since nearly every component has been replaced).



I tried resetting the breakers for grins with no change. Is there anything I can check before calling the heating people?



This is a Carrier system.



To give you an idea of what has been replaced over the last 5 years:



circuit board

coil

gas valve

run capacitor and another capacitor (not named)

inducer assembly

motor and wheel (think this was the squirrel cage)





Thanks,



Andy