1 P 1 High

Ariston 1 P 1 Fault Code

Also written as 1P1 — same fault.

The Ariston 1 P 1 fault code means: your boiler has detected a problem with the water circulation inside the system, which is preventing it from heating your home or water effectively.. It appears on 1 Ariston model in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Primary circuit group signal
Typical repair cost £120-250 (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 1 P 1 fault code

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

Source

Ariston 1 P 1 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 7 July 2026