Ariston 1 0 3 Fault Code
Also written as 103 — same fault.
The Ariston 1 0 3 fault code means: your boiler is struggling to detect water circulation inside the heating system, preventing it from safely heating your home.. It appears on 1 Ariston model in our database.
Technical description: Primary circuit group anomaly
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Ariston models that show the 1 0 3 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ariston 1 0 3 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