BoilerFaultCodesAlpha 0E34 Fault Code
The Alpha 0E34 fault code means: your boiler is struggling because the electricity supply it is receiving is weaker than it should be.. It appears on 3 Alpha models in our database.
Technical description: DHW sensor out of range (measures a temperature outside normal working range.)
What causes the Alpha 0E34 fault?
This fault occurs when the sensor responsible for monitoring your hot water temperature sends an impossible reading to the boiler's internal computer. It is usually caused by the sensor failing internally due to age or a loose connection in the wiring that prevents the signal from reaching the control board.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Alpha models that show the 0E34 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Alpha 0E34 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