BoilerFaultCodesFerroli A26 Fault Code
The Ferroli A26 fault code means: your boiler has detected that the main heat exchanger is getting too hot, likely due to poor water circulation or a buildup of debris, and has shut down to prevent internal damage.. It appears on 6 Ferroli models in our database.
Technical description: Exchanger protection intervention
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 A26 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ferroli A26 fault code information on this page is sourced and cross-checked against the official Ferroli service / installation manuals for each affected model.
- Ferroli Bluehelix HiTech RRT manual (PDF)
- Ferroli Bluehelix Pro RRT manual (PDF)
- Ferroli Bluehelix Tech manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026