HVACopediaICP furnace error codes
19 codes with causes and test steps.
| Code | Meaning | Severity |
|---|---|---|
| 1+2 | Blower on after power-up (normal) | Low |
| 1+5 | Blower motor lockout | High |
| 2 | Pressure switch did not open | Medium |
| 2+5 | Invalid model selection or setup error | Medium |
| 3 | Low pressure switch did not close or reopened | Medium |
| 3+5 | Gas valve fault (modulating valve) | High |
| 4 | Limit circuit fault | High |
| 4+1 | Blower motor fault | High |
| 4+2 | Inducer motor fault | High |
| 4+3 | Low/medium pressure switch open while medium/high switch closed | Medium |
| 5 | Abnormal flame-proving signal | Critical |
| 6 | Ignition proving failure | High |
| 6+1 | Ignition lockout | High |
| 7 | Limit circuit lockout | High |
| 8 | Gas heating lockout | Critical |
| 9 | Medium/high pressure switch or PSR relay did not close or reopened | Medium |
| 10 | Line voltage polarity | Medium |
| LED off | Amber status LED off - no power / blown 3 A fuse | High |
| LED steady ON | Amber LED on solid - control lockout / wrong model plug | High |
Models covered
G9MAE0601714G9MAE0602120G9MAE0801714G9MAE0802120G9MAE1002122G9MAE1202422
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.