Observation:
| Fault Code | LED 3 | LED 4 |
| Lockout | Slow flash | Off |
| Sensor faults | Fast Flash | Off |
| Reverse polarity | Fast Flash alternating | Fast Flash alternating |
FAULT CODES
Examples: LED 3 slow flash (left side), LED 4 fast flash (right side)
Status codes are displayed at certain points during boiler operation, if boiler is showing one of these codes use DIAGNOSIS FROM START SEQUENCE
| Status Code | LED 3 | LED 4 |
| Application of Power | Fast Flash in sync | Fast Flash in sync |
| Waiting for demand | On | On |
| Fan start up | Off | Fast Flash in sync |
| Appliance running | Off | On |
| Pump overrun | On | Off |
If in doubt or your fault code is not shown use DIAGNOSIS FROM START SEQUENCE to avoid misdiagnosis.