Viessmann Vitodens 050-W fault codes
Built 2018 onwards
Entry-level combi.
Codes on the Vitodens 050-W follow the same Viessmann scheme as the rest of the range. Where a code behaves differently on this generation, the code page says so.
Fault codes
All Viessmann codes that apply to this model.
- EAOn most Vitodens models this is low system pressure. Repressurise to 1.2 bar and it is usually the most homeowner-fixable Viessmann fault.Usually simple to fix
- F4The boiler did not detect a flame and has locked out on the gas valve. It needs a Gas Safe registered engineer.Stop — call an engineer
- F9The fan is not reaching the speed the burner control unit requires. The burner is blocked until it does.Get it checked
- F2The temperature limiter has tripped because the boiler got too hot. Water is not carrying heat away and it should stay off until that is resolved.Stop — call an engineer
- A9The condensate drain is blocked and cannot flow freely. Worth checking the external pipe before you call anyone.Get it checked
- F5The fan is not running at the speed the boiler expects, so combustion cannot be verified and the burner is prevented from firing.Get it checked
- E3The flow temperature sensor is reading outside its valid range. Usually the sensor rather than a genuine overtemperature.Get it checked