100 Low

Baxi 100 Fault Code

The Baxi 100 fault code means: your boiler is currently running at maximum power for a performance test and this is a normal status message, not a system failure.. It appears on 4 Baxi models in our database.

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description: Indicator of maximum output during chimney sweep mode

DIY fix possible

Wait for the engineer to finish their testingTurn the selector dial or press the 'Reset' button to exit standard operation modeSwitch the boiler off and back on at the fused spur switch to reset the display

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Baxi models that show the 100 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Baxi 100 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