When the display panel on your Fisher air conditioner flashes strange numbers and letters (like E1, FO or F5) on the display and (or) the operation lamp is blinking, this means that the system is giving you an error code. Error codes are used by repairmen to diagnose the malfunction and repair the system. In many cases you may do it on your own with the help of the table below.
Fisher FSAI-Pro-91AE2 air error codes
| Operation lamp | Timer lamp | Display | LED STATUS |
| ☆ 1 time | X | EO | Indoor unit EEPROM parameter error |
| ☆ 2 times | X | E1 | Indoor / outdoor units communication error |
| ☆ 3 times | X | E2 | Zero crossing signal detection error(except FSAIF-Pro-181AE2) |
| ☆ 4 times | X | E3 | Indoor fan speed has been out of control |
| ☆ 5 times | X | E4 | Open circuit or short circuit of indoor room temperature T1 sensor |
| ☆ 6 times | X | E5 | Open circuit or short circuit of evaporator coil temperature T2 sensor |
| ☆ 7 times | X | EC | Refrigerant Leakage Detection |
| ☆ 2 times | O | F1 | Open circuit or short circuit of outdoor ambient T4 temperature sensor |
| ☆ 3 times | O | F2 | Open circuit or short circuit of condenser coil temperature T3 sensor |
| ☆ 4 times | O | F3 | Open circuit or short circuit of compressor discharge T5 temperature sensor |
| ☆ 5 times | O | F4 | Outdoor unit EEPROM parameter error |
| ☆ 6 times | O | F5 | Outdoor fan speed has been out of control |
| ☆ 1 times | ☆ | PO | IPM malfunction or IGBT over-strong current protection |
| ☆ 2 times | ☆ | P1 | Over voltage or over low voltage protection |
| ☆ 3 times | ☆ | P2 | High temperature protection of compressor top diagnosis and solution(Only FSAI-Pro-241AE2 model) |
| ☆ 5 times | ☆ | P4 | Inverter compressor drive error |
Fisher FSPI-091B air error codes
| Error code | Malfunction |
| EO | Water Pump Malfunction |
| E1 | High pressure protection of compressor |
| E3 | Low pressure protection of compressor |
| E4 | High discharge temperature protection of compressor |
| E5 | Compressor overload or drive error |
| E6 | Communication malfunction |
| E9 | Water overflow protection |
| FO | Indoor unit ambient sensor malfunction at air return opening |
| F1 | Evaporator sensor malfunction |
| F2 | Condenser sensor malfunction |
| F3 | Outdoor unit ambient temperature sensor malfunction |
| F4 | Discharge temperature sensor malfunction |
| F5 | Ambient sensor malfunction on Displayer (or LED board) |