BoilerFaultCodesIdeal Flow/Return reversed Fault Code
Also written as FLOWRETURNREVERSED — same fault.
The Ideal Flow/Return reversed fault code means: your boiler has detected that heat isn't moving through the pipes in the expected direction, which usually means a sensor is loose or has failed.. It appears on 4 Ideal models in our database.
Technical description: Check if flow thermistor is correctly clipped to pipe. Replace flow thermistor.
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 31 August 2026