Observation:
| CODE / | DESCRIPTION | CODE / | DESCRIPTION |
| F00 /F10 | Flow heating temperature sensor fault | F61 to F67 | Fault in the main board |
| F01 / F11 | Return heating temperature sensor fault | F68 | Fluctuation of flame signal |
| F20 | Overheating fault | F70 | User interface incompatible with main PCB |
| F22 | Water pressure of the installation (<0.3 bar) | F71 | Flow heating temperature sensor fault |
| F23 | Max temp difference reached return & flow heating | F72 | Permanent temp difference flow & return sensors |
| F24 | Water circulation fault | F73 / F74 | Heating circuit pressure sensor fault |
| F26 | Fault gas valve motor | F76 | Thermal fuse fault |
| F27 | Flame detection fault | F77 | Fault in gas valve motor |
| F28 | Ignition fault | F83 | No water in system, temp does not increase |
| F29 | Loss of flame during operation | F84 | Permanent temp difference between sensors |
| F32 | Incorrect air pressure | F85 | Flow and return heating sensors fault |
| F49 | Ebus voltage fault | F86 | Under floor heating contact fault |
| Err | User interface fault | RESET | Fault |