Table 1. Fault Codes
| RTEM LED Code | Fault Description |
| Off | No Power or Failure |
| On | Normal - OK to economize |
| Slow Flash | Normal - Not OK to economize |
| Fast Flash | Communications Failure |
| 1 Flash | Actuator Fault |
| 2 Flash | CO2 Sensor |
| 3 Flash | RA Humidity Sensor |
| 4 Flash | RA Temp Sensor |
| 5 Flash | OA Quality Sensor |
| 6 Flash | OA Humidity Sensor |
| 7 Flash | OA Temp Sensor |
| 8 Flash | MA Temp Sensor |
| 9 Flash | RAM Fault |
| 10 Flash | ROM Fault |
| 11 Flash | EEPROM Fault |
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.