BoilerFaultCodesRemeha E09 Fault Code
The Remeha E09 fault code means: your boiler has stopped working because it cannot communicate with the sensor that monitors the temperature of the water returning to the unit.. It appears on 7 Remeha models in our database.
Technical description: Interruption return sensor: check wiring and sensor.
What causes the Remeha E09 fault?
This fault occurs when the boiler's main control board loses the electrical signal from the sensor that monitors the temperature of the water coming back from your radiators. The most common reason is that the sensor has developed an internal electrical failure or the wiring connecting it to the brain of the boiler has become loose or damaged.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Remeha models that show the E09 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Remeha E09 fault code information on this page is sourced and cross-checked against the official Remeha service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026