BoilerFaultCodesAlpha 0A44 Fault Code
The Alpha 0A44 fault code means: your boiler is struggling to accurately measure the temperature of the water returning to it, which causes it to stop operating to stay on the safe side.. It appears on 3 Alpha models in our database.
Technical description: Return sensor out of range. Sensor measures a temperature outside normal working range.
What causes the Alpha 0A44 fault?
This fault occurs when the sensor responsible for monitoring the water returning to the boiler sends a signal that is outside of its expected safety limits. The most common reason is that the sensor has developed an internal electrical fault or the wiring connecting it to the main control board has become damaged. In some cases, it can also be triggered if the water inside the system reaches an extreme temperature that the sensor is unable to process.
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 0A44 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Alpha 0A44 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