Error Code | Code Translation | Action Taken by Unit | Possible Cause |
2 | An extreme low voltage condition exists <198V for 230V units and <239V for 265V units. | Shut down unit. Display Error code and flash. Once voltage rises to normal level system power is restored. | • Inadequate power supply |
| | | • Defective breaker |
| | | • Blown fuse |
3 | Return air thermistor sensor open or short circuit | Set return air sensor = 75°F. Alternately flash set point and error code. Leave unit running. | • Defective sensor |
4 | Indoor coil thermistor sensor open or short circuit | Set ID coil temp = 40°F. Alternately flash set point and error code. Leave unit running. |
5 | Outdoor coil thermistor sensor open Or short circuit | Set OD coil temp = 20°F. Alternately flash set point and error code. Automatically change over to Electric heat Mode only. Leave unit running. |
6 | If O.D. coil Temperature > 175 Deg F for 2 consecutive minutes. (Heat Pump models only) | Alternately flash set point and error code. Shut unit down for 5 minutes, then try again 2 times. If it fails the 3rd time, shut down unit to prevent high head pressure. | • Dirty coil |
| | | • Fan motor failure |
| | | • Restricted air flow |
| | | • Non-condensables in refrigeration system |
7 | I.D coil temperature <30 Deg F for 2 consecutive minutes. | Alternately flash set point and fault code. Continue fan operation while the compressor is locked out until the indoor coil thermistor reaches 45° F, then energize the compressor. However, compressor must stil wait a lockout time of 180 to 240 seconds. | • Dirty filters |
| | | • Dirty coil |
| | | • Fan motor failure |
| | | • Restricted airflow |
| | | • Improper refrigerant charge |
| | | • Restriction in refrigerant circuit |
8 | Unit cycles (Heat or Cool demand) > 9 times per hour | Store error code in memory. Keep unit running | • Unit oversized |
| | | • Low load conditions |
9 | Unit cycles (Heat or Cool demand) < 3 times per hour | Store Error Code in memory. Keep unit running | • Unit undersized |
| | | • High load conditions |
10 | Room Freeze Protection triggered | Alternately flash set point and error code. Keep unit running. | • Room temperature fell below 40° F |
11 | No Signal to “GL” or “GH” terminal (Remote Thermostat mode only) | Shut down unit. Display error code and flash. | • Defective remote thermostat |
| | | • Defective thermostat wiring |
13 | If Pressure limit switch opens | Turn OFF compressor. Alternate flash set point and error code | |