How much does it cost to fix Ariston error code A11?

Typical repair cost for the Ariston A11 fault is £120-250 including labour.

A11 High

Ariston A11 Fault Code

Q: What does the Ariston A11 fault code mean?

Your boiler is struggling to clear air and gases from its internal combustion chamber, so it has safely shut down to prevent unsafe operation.

The Ariston A11 fault code means: your boiler is struggling to clear air and gases from its internal combustion chamber, so it has safely shut down to prevent unsafe operation.. It appears on 9 Ariston models in our database.

Technical description: Air Pressure Switch

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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Ariston models that show the A11 fault code

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

Challenger 80E Repair: £150-250
Clas One Repair: £80-150
E-Combi One Repair: £150-250
E-Combi One 30 Repair: £150-250
Euro Combi 30 MFFI Repair: £180-320
Euro Prisma 24 Repair: £180-350
Genus 24 MFFI Repair: £120-250
Micro Combi 27 MFFI Repair: £120-250
Microsystem 15 Repair: £150-250

Source

Ariston A11 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