Extremely high or low temperatures add to the air conditioner’s workload, making the system more prone to malfunctions. Check whether you can see a fault code flashing on the display. It is very likely that it will help diagnose the problem. Using the list of Friedrich air error codes below, try to resolve the issue by yourself first. Chances are you won’t have to call for service at all.
| Error code | Error contents |
| 13 | Outdoor signal abnormal |
| 14 | Excessive outdoor pressure (permanent stop) |
| 15 | Compressor temperature sensor |
| 16 | Pressure switch error |
| 17 | IPM error |
| 18 | CT error |
| 19 | Active filter module (AFM) error |
| 1A | Compressor does not operate |
| 1b | Outdoor unit fan error |
| 1c | Communication error (inverter-multicontroller) |
| 1d | 2 way valve sensor error |
| 1E | Expansion valve error |
| 1F | Connection indoor unit error |
| 0 | Communication error (indoor unit — remote controller) |
| 1 | Communication error (indoor unit — outdoor unit) |
| 2 | Room temperature sensor open |
| 3 | Room temperature sensor short-circuited |
| 4 | Indoor heat exchanger temperature sensor open |
| 5 | Indoor heat exchanger temperature sensor short- circuited |
| 6 | Outdoor heat exchanger temperature sensor |
| 8 | Power source connection error |
| 9 | Float switch operated |
| 0A | Outdoor temperature sensor |
| 0c | Discharge pipe temperature sensor |
| 11 | Model abnormal |
| 12 | Indoor fan abnormal |
| 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 |
| LEO | Error contents |
| 1 flash | Communication error (Indoor unit – Outdoor unit) |
| 2 flash | Discharg pipe temperature sensor |
| 3 flash | Outdoor heat exchanger temperature sensor |
| 4 flash | Outdoor temperature sensor |
| 5 flash | 2 way valve sensor |
| 6 flash | 3 way valve sensor |
| 7 flash | Compressor temperature sensor |
| 8 flash | Heat sink temperature sensor |
| 9 flash | Pressure switch A abnormal |
| 10 flash | Pressure switch B abnormal |
| 11 flash | Connection indoor unit error |
| 12 flash | IPM orror |
| 13 flash | Compressor rotor position cannot detect |
| 14 flash | Compressor cannot operate |
| 15 flash | Outdoor fan abnormal |
| 17 flash | Communication error (inverter – mufti controller) |
| lighting | No error |