BoilerFaultCodesPotterton A33 Fault Code
The Potterton A33 fault code means: your boiler has stopped working because the internal fan, which safely pushes exhaust gases out of the flue, is not spinning at the correct speed.. It appears on 1 Potterton model in our database.
Technical description: Fan speed incorrect. Check fan wiring and connections. Replace fan Part No. 5106068 or boiler control
What causes the Potterton A33 fault?
This fault occurs when the boiler’s internal computer detects that the fan is not spinning at the required speed to safely clear waste gases from the system. The most common reason is that the fan motor has physically burnt out or become seized, though it can also be caused by loose wiring or a failing control board that is sending incorrect signals to the motor.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Potterton models that show the A33 fault code
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Source
Potterton A33 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