How much does it cost to fix Ariston error code 40-60-70 (ll-ll-ll)?

Typical repair cost for the Ariston 40-60-70 (ll-ll-ll) fault is £150-250 including labour.

40-60-70 (ll-ll-ll) High

Ariston 40-60-70 (ll-ll-ll) Fault Code

Q: What does the Ariston 40-60-70 (ll-ll-ll) fault code mean?

Your boiler has detected that a safety switch is stuck in the wrong position, which prevents it from starting to avoid any risk of incorrect combustion.

Also written as 406070LLLLLL — same fault.

The Ariston 40-60-70 (ll-ll-ll) fault code means: your boiler has detected that a safety switch is stuck in the wrong position, which prevents it from starting to avoid any risk of incorrect combustion.. It appears on 4 Ariston models in our database.

Technical description: Fan off but air pressure switch fails to return to off position

Typical repair cost £150-250 (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 40-60-70 (ll-ll-ll) fault code

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

Source

Ariston 40-60-70 (ll-ll-ll) 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