Just noticed my AC isn't turning on. It's a 2 year old system. I've tried rebooting from the thermostat, but nothing is happening. I also see that my dehumidifier is not kicking on either. Fan is set to auto, and it's not running. If I set it to 'on' my thermostat will tell me that it is running. Any thoughts? Thanks to everyone for their input.

Equipment:

Thermostat: Lennox S30 Thermostat
HVAC: Lennox EL18XCV 4-ton
Furnace: Lennox EL296V
Dehumidifier: Healthy Climate 80 pint

Did you check the breaker to make sure the unit has power? I think those T-stats are/can be battery powered.

Well, looks like I had to get up in the attic and reboot the communicating router. Everything appears to be up and running.

Yeah. That was my first go to. Thank you for the suggestion.