Upon arrival inspected system and found multiple critical errors and multiple other errors. Upon further inspection found AXB board will not communicate. As well as thermostat. Homeowners informed me they removed stat from the wall and replaced it trying to restart system and after that stat got hot and went blank. Communication error present for AXB and thermostat. Install t4 stat and start system under emergency auxiliary heat. Allowing system to operate under emergency functions until system can be further inspected and repaired or replaced due to repair costs.