How much does it cost to fix Heatline error code P.01?

Typical repair cost for the Heatline P.01 fault is £80-120 including labour.

P.01 Low

Heatline P.01 Fault Code

Q: What does the Heatline P.01 fault code mean?

Your boiler has entered a special testing mode where it is running at maximum power, likely due to a manual override or a configuration setting, rather than a standard mechanical fault.

Also written as P01 — same fault.

The Heatline P.01 fault code means: your boiler has entered a special testing mode where it is running at maximum power, likely due to a manual override or a configuration setting, rather than a standard mechanical fault.. It appears on 7 Heatline models in our database.

Technical description: Forcing the burner (Pmin) to (Pmax.)

Typical repair cost £80-120 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Heatline models that show the P.01 fault code

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

Source

Heatline P.01 fault code information on this page is sourced and cross-checked against the official Heatline service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026