| Pattern | Meaning | Severity |
|---|---|---|
| 1 flash | high | |
| 1 flash | critical | |
| 1 flash | info | |
| 2 flashes | high | |
| 2 flashes | high | |
| 2 flashes | info | |
| 3 flashes | high | |
| 3 flashes | high | |
| 4 flashes | high | |
| 5 flashes | critical | |
| 6 flashes | medium | |
| 7 flashes | high | |
| 8 flashes | high | |
| 9 flashes | medium | |
| 10 flashes | critical |
| Code | Description | Severity |
|---|---|---|
| 13 | Limit Circuit Lockout | critical |
| 14 | Ignition Lockout | critical |
| 21 | Gas Heating Lockout | critical |
| 23 | Pressure Switch Stuck Open | critical |
| 24 | Secondary Voltage Fuse Open | warning |
| 31 | High Pressure Lockout | critical |
| 32 | Low Pressure Lockout | critical |
| 33 | Compressor Thermal Lockout | critical |
| 34 | Ignition Proving Failure | high |
| 41 | Blower Motor Fault | high |
| 42 | Inducer Motor Fault | high |
| 44 | Blower Running After Power Interruption | low |
| 45 | Lockout - Control Circuit Failure | critical |
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