Viessmann Vitodens 100W boiler error code E3

Hello Everybody,

My seven years old Viessmann Vitodens 100 is continuously displaying an E3 error code. I have tried to find out the hidden meaning behind this error code after reading the user manual but did not get it. Someone please me to sort out this problem.

Your suggestions will be highly appreciated

Thanks a lot


Hi Gabriel, an E3 error code on your Viessmann Vitodens 100W boiler deals with the “wrong adjustment of a combustion controller”. For rectifying the problem, you have to follow the below given steps:

  • Firstly, ensure sufficient heat transfer & press a reset button
  • Secondly, verify the current gap between burner gauze & ionization electrode assembly
  • Afterward, verify the distribution of the gas type  
  • Finally, verify the ventilation shaft system & remedy the recirculation of the flue gas if needed