Ariston B08 Fault Code
The Ariston B08 fault code means: your boiler is having trouble communicating with its internal timer, which means your scheduled heating programs may not turn on or off as expected.. It appears on 2 Ariston models in our database.
Technical description: Time Clock
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 B08 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ariston B08 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 31 August 2026