Posted 29th January, 2025 at 20:43 by Matthew Varlow
When the Multi Control or Smart Control shows error T12 this is a commication error, the controller cannot see the heater.
To fix this error, on a Air Top heater, you need to make sure the controller is connected to the Telestart, Thermocall, Diagnose plug (x9c). This is not the same plug the Rotary Rheostat connects.
You may also need to reset and select the correct heater version. To do this -
- Go to 'settings' > 'reset' > confirm 'ok'
- When the screen goes blank, press and hold both buttons.
- Screen should display 'heater'
- Manually select the heater version you are using the controller with.
For more information on this fault code see links below.
Watch the Butler Technik YouTube video - How to fix Webasto T12 Multi Control error fault code - 5 steps | Butler Technik
Read the technical blog article - How to Fix a Webasto Multi Control T12 Fault Error Message | Butler Technik
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