F51 High

Ferroli F51 Fault Code

The Ferroli F51 fault code means: your boiler's main internal computer has developed a fault and can no longer control the heating or hot water safely.. It appears on 3 Ferroli models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Controller DBM23B error – controller could have an internal error
Typical repair cost £250-£450 (including labour)

Engineer required

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

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Ferroli models that show the F51 fault code

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

Source

Ferroli F51 fault code information on this page is sourced and cross-checked against the official Ferroli service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026