602 High

Warmflow 602 Fault Code

The Warmflow 602 fault code means: your boiler's water circulation pump is struggling or has failed, meaning your heating and hot water will not work correctly.. It appears on 1 Warmflow 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: Grundfoss 15/60 Pump (for replacement head)
Typical repair cost £250-400 (including labour)

Engineer required

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

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Warmflow models that show the 602 fault code

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

Source

Warmflow 602 fault code information on this page is sourced and cross-checked against the official Warmflow service / installation manuals for each affected model.

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