Viessmann boiler error a9
This boiler error message is often a result of a bad sensor or dirty burner.
Viessmann boilers are some of the most efficient in the industry and, with proper maintenance, will last for many years.
This article will cover each type of boiler error message and how to fix them.
1) The sensor could be faulty.
2) There could be dirt or limescale blocking the sensor.
3) The boiler may not supply enough water, so there is no hot water or steam to operate the heating system and hence no heating radiators.
Viessmann is the world’s leading supplier of condensing and non-condensing boilers and product lines for heating, process heat and power generation.
To fix this issue, follow these steps:
1. Check for leaks in plumbing or any place where water leaks.
2. If there are no leaks and you have already run the Viessmann boiler error a9 code, go to step 3.
3. Check which pump is on, as there should be one on when it’s running; if neither is running then turn them both on and wait 15 minutes for them to restart automatically from their timers to check if they will work at all now
4. If neither pump starts up, make sure both pumps are set for manual operation and turn them