| American Standard Error Code | What this means |
|---|---|
| 2 flashes | The furnace is likely blowing cold air because it’s dropping the flame. |
| 3 flashes | Indicates a problem with the pressure switch. |
| 4 flashes | Indicates a problem with the limit switch. |
| 6 flashes | Indicates a problem with the polarity or grounding. |
| 7 flashes | Indicates a problem with the gas valve. |
| 9 flashes | Indicates a problem with the ignition or the ignitor circuit. |
| 22 flashes | Indicates a problem with the flame itself. |