How much does it cost to fix Ariston error code AUTODIAGNOSIS FAULTY?

Typical repair cost for the Ariston AUTODIAGNOSIS FAULTY fault is £180-350 including labour.

AUTODIAGNOSIS FAULTY High

Ariston AUTODIAGNOSIS FAULTY Fault Code

Q: What does the Ariston AUTODIAGNOSIS FAULTY fault code mean?

Your boiler's internal computer has detected a general processing error and cannot tell exactly what is wrong, causing the system to stop working for safety.

Also written as AUTODIAGNOSISFAULTY — same fault.

The Ariston AUTODIAGNOSIS FAULTY fault code means: your boiler's internal computer has detected a general processing error and cannot tell exactly what is wrong, causing the system to stop working for safety.. It appears on 1 Ariston model in our database.

Technical description: Indicator in TCS flow chart

Typical repair cost £180-350 (including labour)

Engineer required

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

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Ariston models that show the AUTODIAGNOSIS FAULTY fault code

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

Egis 24 MFFI Repair: £180-350

Source

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

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