Viessmann Vitodens Tec Fault Codes

Combi Natural GasLPG 19-35 kW 2012-2015 Discontinued

GC Numbers: 47-819-2447-819-25

Replaced by: Vitodens 100-W

The fault code is already on your display

Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →

Most common fault codes

Code	Severity	Plain English	DIY
A9	High	Your boiler is having trouble 'talking' to its internal pump, which means it cannot flow water around the system to heat your home.	Engineer
b0	High	Your boiler has paused its initial setup process because the automatic air-venting sequence has not finished successfully.	Yes
b1	High	Your boiler is currently stuck in an incomplete setup mode, meaning the installation process wasn't fully finished or the system hasn't been properly coded.	Engineer
b4	High	Your boiler has not been fully configured for operation or there is a communication problem between the internal controls and the burner assembly.	Engineer
b5	High	Your boiler has failed to complete its initial setup process, meaning it hasn't properly cleared air from the system or finished its first startup sequence.	Engineer
b9	High	Your boiler has likely been left in a testing mode used during installation or there is a fault with the gas ignition valve.	Engineer
EE	High	Your boiler has detected a problem while trying to light the flame or keep it burning, causing it to shut down for safety.	Yes
EF	High	Your boiler is continuing to detect a flame even after it has been told to shut down, which is a safety precaution to prevent gas issues.	Engineer

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