BoilerFaultCodesRemeha E31 Fault Code
The Remeha E31 fault code means: your boiler has detected a problem with the sensor that measures hot water temperature, which often means your hot water may be cold or inconsistent.. It appears on 8 Remeha models in our database.
Technical description: DHW temperature sensor error (S3)
What causes the Remeha E31 fault?
This fault occurs when the boiler's control board loses communication with the sensor responsible for monitoring your hot water temperature. The most common reason is that the internal components of the sensor have failed due to age, or the electrical connection has become loose or corroded. Because the boiler can no longer tell how hot the water is, it shuts down as a safety precaution to prevent overheating.
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 E31 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Remeha E31 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