A-1 High

Ferroli A-1 Fault Code

Also written as A1 — same fault.

The Ferroli A-1 fault code means: your boiler is failing to detect any power, meaning it has completely shut down and cannot heat your home or provide hot water.. It appears on 2 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: No mains electricity/switches off/fuse blown.
Typical repair cost £80-150 (including labour)

DIY fix possible

Check your consumer unit (fuse box) to see if the boiler's circuit breaker has tripped.Check the fused spur switch located near the boiler to ensure it is in the 'on' position.Check the fuse inside the fused spur switch to see if it has blown.

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Ferroli models that show the A-1 fault code

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

Source

Ferroli A-1 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