To Next PageTo Next PageWhy is my Viessmann B2TB004 Boiler showing fault code bb?
If your Viessmann Boiler displays fault code bb, it indicates a communication error with the extension kit for heating circuit 3 (with mixer). Check extension kit connections and code.
How to fix fault code bC on Viessmann B2TB004 Boiler?
If your Viessmann Boiler displays fault code bC, it indicates a communication error with the remote control Vitotrol heating circuit 1 (without mixer). Check connections, lead, coding address "A0" and remote control settings.
What does error code Ed mean on a Viessmann B2TB004?
If your Viessmann Boiler displays error code Ed, it indicates an internal fault. To resolve this, replace the control unit.
What does error code E5 mean on a Viessmann B2TB004 Boiler?
If your Viessmann Boiler displays error code E5, it indicates a fault with the flame amplifier. To resolve this, replace the control unit.
What does error code E4 mean on my Viessmann B2TB004 Boiler?
If your Viessmann Boiler displays error code E4, it indicates a fault in the supply voltage of 24 V. To resolve this, replace the control unit.
What does Fault Code dA mean on my Viessmann B2TB004 Boiler?
If your Viessmann Boiler displays Fault Code dA, there is a short circuit in the room temperature sensor for heating circuit 1 (without mixer). Check the room temperature sensor for heating circuit 1.
What causes fault code C3 on a Viessmann B2TB004 Boiler?
If your Viessmann Boiler displays fault code C3, it indicates an Extension AM1 communication error. Check electrical connections.
How do I fix fault code C4 on my Viessmann B2TB004 Boiler?
If your Viessmann Boiler displays fault code C4, it indicates a communication error with the Open Therm extension. Check Open Therm extension.
What does fault code C5 mean on a Viessmann B2TB004 Boiler?
If your Viessmann Boiler displays fault code C5, it indicates a communication error with the variable speed internal pump. Check the setting of coding address "30".
What should I do if my Viessmann B2TB004 Boiler shows fault code C6?
If your Viessmann Boiler displays fault code C6, it indicates a communication error with the external variable speed heating circuit pump, heating circuit 2 (with mixer). Check setting of coding address "E5".
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