How much does it cost to fix Ariston error code 50 (ll)?

Typical repair cost for the Ariston 50 (ll) fault is £150-350 including labour.

50 (ll) High

Ariston 50 (ll) Fault Code

Q: What does the Ariston 50 (ll) fault code mean?

Your boiler is struggling to move water through the system, either because the flow is blocked or the internal pump is not working correctly.

Also written as 50LL — same fault.

The Ariston 50 (ll) fault code means: your boiler is struggling to move water through the system, either because the flow is blocked or the internal pump is not working correctly.. It appears on 4 Ariston models in our database.

Technical description: Primary water circulation defect

Typical repair cost £150-350 (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 50 (ll) fault code

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

Source

Ariston 50 (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