Viessmann boiler error code 99
There are three possible outcomes of a viessmann boiler error code 99.
1) Boiler can’t be started: This is shown by the red LED flashing ten times in succession, then the LED will start flashing fast, which means the boiler control board has detected an error and can’t be started.
2) Boiler will not activate after 15 seconds: this is indicated by a red LED flashing once every 3 seconds and corresponds to an error code 99-1.
3) Boiler will not activate after 60 seconds: this is indicated by a red LED flashing once every 3 seconds and corresponds to an error code 99-2.
The error code 99 indicates that the boiler is not working properly, and the problem should be addressed. This can happen because of an issue with the water pressure or the controller board.
No need to worry! There are a few steps to help you solve this problem, so let’s look at them.