BoilerFaultCodesBaxi H.02.12 Fault Code
Also written as H0212 — same fault.
The Baxi H.02.12 fault code means: your boiler has been told to stop running by an external safety device or control, such as a thermostat or a condensation pump, which has detected an issue.. It appears on 2 Baxi models in our database.
Technical description: Control unit input contact opened by external device
DIY fix possible
Check if your thermostat or programmer is calling for heat and has working batteries.If you have a condensate pump, check if it is full or blocked, as it may have triggered a safety shut-off.Reset the boiler using the control knob to see if the error clears.
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Baxi models that show the H.02.12 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Baxi H.02.12 fault code information on this page is sourced and cross-checked against the official Baxi service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026