How much does it cost to fix Ariston error code 50-80 (ll-ll)?

Typical repair cost for the Ariston 50-80 (ll-ll) fault is £120-200 including labour.

50-80 (ll-ll) High

Ariston 50-80 (ll-ll) Fault Code

Q: What does the Ariston 50-80 (ll-ll) fault code mean?

Your boiler has lost the ability to measure the temperature of your hot water, so it has safely stopped heating to prevent it from getting too hot.

Also written as 5080LLLL — same fault.

The Ariston 50-80 (ll-ll) fault code means: your boiler has lost the ability to measure the temperature of your hot water, so it has safely stopped heating to prevent it from getting too hot.. It appears on 4 Ariston models in our database.

Technical description: D.H.W.thermistor faulty (open cicrcuit)

Typical repair cost £120-200 (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 50-80 (ll-ll) fault code

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

Source

Ariston 50-80 (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