In the unfortunate event that your Viessmann boiler develops an issue, it will display a fault code. So that you can quickly identify what the fault code means and what should be your next course of action, we have developed the below fault code finders for the Viessmann range.
Just look below for the fault code that your boiler is displaying and the fault code finder will provide you with a diagnosis, this will assist you should you need to contact an engineer.
Common Viessmann Fault Codes
| Error code | Boiler Model | Description |
|---|---|---|
| Code: 10 | Vitodens 200-W / 222-F / 200 / 200-H | Operation on outdoor temperature of 0°C. Short circuit on outdoor temperature sensor. |
| Codes: 18 and D1 | Vitodens 100 / 100-W / 200-W / 222-F | Operation constant at outdoor temperature of 0°C. Outdoor sensor cable broken. |
| Codes: 20 | Vitodens 200-W/222-F | Regulates without the temperature sensor. Short-circuit in the supply temperature sensor. |
| Codes: 90, 91, 92, 93, 94, 98, 99, 9A, 9B, 9C, 9E, 9F and AB | All Viessmann Boilers | Boiler is in ‘control’ mode due to temperature sensor short-circuit. |
| Codes: A0, A1, A2, AA and AC | Vitodens 200 | Pump running at maximum speed. Open circuit. |
| Codes: A4 | Vitodens 222F | Burner blocker – air lock in pump or flow rate not possible. |
| Codes: A9, BA, BB, BC and FE0 | Vitodens 200 | Boiler is cooling down due to sensor inputs not reading correctly |
| Code: D4 | Vitodens 200 | Emergency mode, or boiler cools down. Internal fault or open circuit. |
| Codes: E1, E7, E8, E9, EA, EB, EC and FF2 | Vitodens 200-W/222-F | Burner control unit in fault moode due to low flow rate. |
| Codes: F6, F9, 58, F-E1, F-E2 and F-F6 | All Viessmann Boilers | Burning in fault mode. Fan not at standstill. |
