BoilerFaultCodesAlpha 0E81 Fault Code
The Alpha 0E81 fault code means: your boiler's temperature sensors are giving conflicting readings, causing the system to stop operating safely to prevent potential overheating.. It appears on 3 Alpha models in our database.
Technical description: Flow and return sensor anomaly detected. The sensor shows an incorrect temperature value.
What causes the Alpha 0E81 fault?
This fault occurs when the boiler's internal computer receives contradictory information from the sensors that monitor water temperature. It usually happens because one of the sensors has failed or developed a electrical 'drift', meaning it is reporting a temperature that is physically impossible or vastly different from its partner sensor. To prevent the unit from overheating or operating unsafely, the system shuts down until the faulty component is replaced.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Alpha models that show the 0E81 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Alpha 0E81 fault code information on this page is sourced and cross-checked against the official Alpha service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026