Table 1. Fault Codes
| Green System LED (Ignition Board) Error Code | Fault Description | Possible Issue |
| On | Normal - no call for heat | N/A |
| Slow Flash | Active call for heat | N/A |
| Fast Flash | Not communicating with RTRM | Wiring issue or problem with ignition module or RTRM |
| 2 Flash | System lockout - failure to sense flame | Failure to ignite, no spark, low/no gas pressure |
| 4 Flash | TCO (high temperature limit) circuit open | excessive heat in the combustion chamber, low airflow, |
| 5 Flash | Flame being sensed, but gas valve not energized | stuck gas valve |
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.