BoilerFaultCodesMain 22 Fault Code
The Main 22 fault code means: your boiler has stopped working because it cannot detect the flow of air required to safely vent exhaust gases, so it has shut down to prevent unsafe operation.. It appears on 2 Main models in our database.
Technical description: Fault on Fan or Flue
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Main models that show the 22 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Main 22 fault code information on this page is sourced and cross-checked against the official Main service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026