How much does it cost to fix Ferroli error code B-6?

Typical repair cost for the Ferroli B-6 fault is £120-250 including labour.

B-6 High

Ferroli B-6 Fault Code

Q: What does the Ferroli B-6 fault code mean?

Your boiler has stopped working because it has detected an issue with its water pressure or internal temperature monitoring systems.

Also written as B6 — same fault.

The Ferroli B-6 fault code means: your boiler has stopped working because it has detected an issue with its water pressure or internal temperature monitoring systems.. It appears on 2 Ferroli models in our database.

Technical description: C.H. sensor (34) short circuit or resistance lower than 500 ohm. C.H. limit thermostat (50) open circuit (pump will run). C.H. water pressure low (114 open circuit)

Typical repair cost £120-250 (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 B-6 fault code

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

Source

Ferroli B-6 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