Viessmann Fault Codes
Searchable list
Boilers covered:
- Vitodens 025-W
- Vitodens 050-W
- Vitodens 100-W Combi
- Vitodens 100-W System
- Vitodens 100-W Heat Only
- Vitodens 111-W
- Vitodens 200-W Combi
- Vitodens 200-W System
- Vitodens 200-W Heat Only
- Vitodens 222-F
- Earlier Vitodens 050-W BPJD
- Vitodens 100-W B1HA/B1KA
- Vitodens 100-W B1HC/B1KC
- Vitodens 300-W
Note: Low-pressure codes (EA, E1, E6) may be user-fixable. Most others require a Gas Safe engineer.
Modern Codes (F-series)
| Error code | Possible fault | If ticked try the troubleshooter |
|---|---|---|
| F1 | Burner fault / maximum flue gas temperature exceeded | ✓ |
| F2 | Burner lockout / overheat (temperature limiter responded) | ✕ |
| F3 | Flame signal already present at burner start | ✕ |
| F4 | No flame detected / ignition failure | ✓ |
| F5 | Flue overheat / air pressure switch fault | ✕ |
| F8 | Gas valve closes too late | ✕ |
| F9 | Fan speed too low / fan fault | ✕ |
| FA | Fan not at standstill | ✕ |
| FC | Burner control unit fault | ✕ |
| FD | System water pressure too high | ✓ |
Classic Codes (numeric / E-series)
| Error code | Possible fault | If ticked try the troubleshooter |
|---|---|---|
| 02 | Safety chain activation | ✕ |
| 04 | Fan speed fault | ✕ |
| 0A | Flame established but lost / gas pressure too low | ✕ |
| 0D | Gas valve fault / fan speed fault | ✕ |
| 10 | Outside temperature sensor short circuit | ✕ |
| 30 | Boiler water temperature sensor short circuit | ✕ |
| E1 | Low water pressure / pressure sensor fault | ✓ |
| E8 | Outside temperature sensor fault | ✕ |
| EA | Water pressure too low / ignition lockout | ✓ |
| A2 | KM-BUS fault to Vitocom | ✕ |