BoilerFaultCodesAlpha E77 Fault Code
The Alpha E77 fault code means: your boiler is correctly identifying that the internal mechanism responsible for controlling the flow of gas to the burner isn't receiving the necessary electrical signal, causing the boiler to stop working to ensure safety.. It appears on 18 Alpha models in our database.
Technical description: Low current through gas valve modulator
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 E77 fault code
Click a model for the full fault code list and model-specific repair notes.
- C25 Xtraflame Repair: £150-300
- 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 24 Repair: £150-250
- E-Tec Plus 28 Repair: £150-250
- E-Tec Plus 33 Repair: £150-250
- E-Tec R Repair: £120-250
- Evoke Repair: £150-300
- Evoke 10 / 18 Repair: £180-350
- H25 Xtraflame Repair: £150-300
- Intec 28GS Repair: £150-300
- Intec 40GS2 Repair: £180-350
- Intec 50CS Repair: £150-300
- Pro Tec 24 Repair: £150-300
- Pro Tec Plus Repair: £150-300
Source
Alpha E77 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