P11 Medium

Alpha P11 Fault Code

The Alpha P11 fault code means: your boiler is displaying a status alert indicating that an internal moisture protection setting has been activated to protect sensitive electrical components.. It appears on 2 Alpha models in our database.

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description: Anti humidity setting
Typical repair cost £120-200 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Alpha models that show the P11 fault code

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

Source

Alpha P11 fault code information on this page is sourced and cross-checked against the official Alpha service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026