BoilerFaultCodesPotterton A02 Fault Code
The Potterton A02 fault code means: your boiler is failing to light the gas even though it is trying to start up.. It appears on 2 Potterton models in our database.
Technical description: Refer to fault finding section on Page 30 (displayed when control fails to detect flame after ignition attempts).
What causes the Potterton A02 fault?
This fault occurs when the boiler tries to start but can’t establish a steady flame to begin heating. It is usually caused by a worn-out ignition part not creating a spark or a gas valve that isn't opening properly to let fuel into the burner. Over time, soot or wear on the internal sensors can also prevent the boiler from 'seeing' the flame even if it has lit.
DIY fix possible
Check that your gas emergency control valve is in the 'On' positionCheck if other gas appliances in your home, like a hob, are working correctlyPress the reset button once to see if the boiler restarts
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Search the official register for a qualified engineer in your area.
Gas Safe Register →Potterton models that show the A02 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Potterton A02 fault code information on this page is sourced and cross-checked against the official Potterton service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026