FLOW/RETURN REVERSED High

Ideal FLOW/RETURN REVERSED Fault Code

Also written as FLOWRETURNREVERSED — same fault.

The Ideal FLOW/RETURN REVERSED fault code means: your boiler has detected that the water pipes supplying heat to your home have been connected the wrong way around or a temperature sensor has been installed in the wrong location.. It appears on 8 Ideal models 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: Check if Flow Thermistor correctly clipped to pipe
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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Ideal models that show the FLOW/RETURN REVERSED fault code

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

Source

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

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