BoilerFaultCodesAlpha 05 Fault Code
The Alpha 05 fault code means: your boiler has detected a problem with the internal sensor that monitors the temperature of the water heading to your radiators, causing the system to stop working for safety.. It appears on 23 Alpha models in our database.
Technical description: Heating flow sensor fault
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Search the official register for a qualified engineer in your area.
Gas Safe Register →Alpha models that show the 05 fault code
Click a model for the full fault code list and model-specific repair notes.
- C25 Xtraflame Repair: £120-220
- CD Repair: £120-200
- E-Tec Repair: £150-250
- E-Tec 24 Repair: £150-250
- E-Tec 28 Repair: £150-250
- E-Tec 33 Repair: £150-250
- E-Tec Plus Repair: £150-250
- E-Tec Plus 10 / 18 Repair: £90-160
- E-Tec Plus 24 Repair: £150-250
- E-Tec Plus 28 Repair: £150-250
- E-Tec Plus 33 Repair: £150-250
- E-Tec R Repair: £150-250
- Eco Repair: £120-200
- Eco 11 13 Repair: £90-160
- Evoke Repair: £150-250
- Evoke 10 / 18 Repair: £90-160
- H25 Xtraflame Repair: £120-220
- Intec 24GS Repair: £150-250
- Intec 28GS Repair: £120-220
- Intec 40GS2 Repair: £120-220
- Intec 50CS Repair: £120-220
- Intec2 25 28XE Repair: £150-250
- Intec2 30SE Repair: £150-250
Source
Alpha 05 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