Boiler displays fault code A2 or A4 on Vitodens 200
Applies to: Vitodens 200, WB2B Series (all models)
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The boiler is operating, but fault code "A2" or "A4" is displayed on the boiler control.
Fault will not clear when the reset button is pressed.
Coding addresses not listed in the manual were mistakenly changed from the factory default settings.
If fault code A2 is displayed, then change the value at coding address "0D" to "0".
If fault code A4 is displayed, then change the value at coding address "0E" to "0".
Then press the reset button to restart the boiler.
- Viessmann Technical Services
- Bulletin ID:
- Date issued:
October 12, 2016
- Updated on:
January 12, 2018
- Revision #: