BoilerFaultCodesAlpha E03 Fault Code
The Alpha E03 fault code means: your boiler has detected that the gases leaving through your flue are too hot, suggesting it is working inefficiently or struggling to vent heat properly.. It appears on 16 Alpha models in our database.
Technical description: High flue temperature
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Alpha models that show the E03 fault code
Click a model for the full fault code list and model-specific repair notes.
- CD S Repair: £120-250
- E-Tec 28 Repair: £120-250
- E-Tec 33 Repair: £120-250
- E-Tec NXS Repair: £150-300
- E-Tec Plus Repair: £120-250
- E-Tec Plus 10 / 18 Repair: £120-280
- E-Tec Plus 28 Repair: £120-250
- E-Tec Plus 33 Repair: £120-250
- E-Tec Regular Repair: £150-300
- E-Tec S Repair: £150-300
- Evoke Repair: £120-250
- Evoke 10 / 18 Repair: £120-250
- Intec 40GS2 Repair: £120-250
- Intec 50CS Repair: £150-300
- Intec2 25 28XE Repair: £120-250
- Intec2 30SE Repair: £120-250
Source
Alpha E03 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 7 July 2026