BoilerFaultCodesAlpha 04 Fault Code
The Alpha 04 fault code means: your boiler has detected an electrical connection problem between the main control board and the gas valve, meaning it cannot safely ignite to provide heat or hot water.. It appears on 23 Alpha models in our database.
Technical description: Gas valve wiring circuit fault detected
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 →Avoid the next call-out bill
A cover plan would handle faults like 04: no call-out fees, no surprise bills.
Affiliate links. We may earn a commission at no extra cost to you.
Alpha models that show the 04 fault code
Click a model for the full fault code list and model-specific repair notes.
- Cd50s Cd70s Repair: £150-300
- E-Tec 28
- E-Tec 33
- E-Tec NX Repair: £180-350
- E-Tec NXS Repair: £140-£320
- E-Tec Plus 28
- E-Tec Plus 33
- E-Tec Plus 38
- E-Tec Plus NX Repair: £120-£280
- E-Tec Regular Repair: £120-250
- E-Tec S Repair: £140-£320
- Eco Repair: £120-250
- Eco 11 13 Repair: £120-£350
- Evoke Repair: £150-£250
- Evoke 10 / 18 Repair: £140-£350
- Evoke NX Repair: £140-£320
- Intec 30GS Repair: £150-250
- Intec 40GS Repair: £150-250
- Intec 50CS Repair: £120-250
- Intec S Repair: £150-250
- Intec² 20SE Repair: £150-250
- Intec2 25 28XE Repair: £120-250
- Intec² 30SE Repair: £150-250
Source
Alpha 04 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 31 August 2026