| E1 | Loss of communication between the CCC 2 thermostat and all system power module boards. System will shut down. |
| Loss of communication between the CCC 2 thermostat and an individual system power module board. The LED will display error code E1 and the zone number that lost communication. Any additional zones that lose communication will blink in addition to the current zone. |
| E2 | Open circuit or out-of-range Indoor Temperature Sensor. All heat, cool, and dehumidify operation will be locked out. Manual fan operation can continue. |
| E3 | Shorted Indoor Temperature Sensor. All heat, cool, and dehumidify operation will be locked out. Manual fan operation can continue |
| E4 | Open circuit or out of range Outdoor Temperature Sensor (Select Models). Heat pump and dehumidification operation will be locked out. Air conditioner, furnace, heat strip, and fan operation can continue to operate |
| E5 | Open circuit or out of range Freeze Sensor (Select Models). Air conditioner and dehumidification operation will be locked out. Heat pump, furnace, heat strip, and fan operation can continue to operate but displays the last temperature set-point |
| E6 | Open circuit Humidity Sensor (Select Models). Air conditioner and dehumidification operation will be locked out. Heat pump, furnace, heat strip, and fan can continue to operate |
| E7 | Loss of 120 VAC power to all power module boards on the system. The system will shut down |
| E8 | Invalid zone configuration. The heat pump and heat strip DIP switches are both set to the ON position in one zone. Heat pump, heat strip, air conditioner, and dehumidify operation will be locked out in the affected zone |
| E9 | Invalid zone configuration. The dehumidifier DIP switch and either the heat pump or heat strip DIP switches are set to the ON position in one zone. Heat pump, heat strip, air conditioner, and dehumidify operation will be locked out in the affected zone |