70 ❍, yellow ❍ Low

Ariston 70 ❍, yellow ❍ Fault Code

Also written as 70YELLOW — same fault.

The Ariston 70 ❍, yellow ❍ fault code means: your boiler is struggling to read the outdoor temperature, which may cause your heating to run less efficiently or not respond correctly to the weather.. It appears on 1 Ariston model in our database.

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description: External sensor circuit open / short circuit
Typical repair cost £100-200 (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 70 ❍, yellow ❍ fault code

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

Source

Ariston 70 ❍, yellow ❍ 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