BoilerFaultCodes E20 Emergency
Alpha E20 Fault Code
The Alpha E20 fault code means: your boiler is detecting a flame inside the unit when it should be switched off, which is a safety concern that prevents it from starting up correctly.. It appears on 21 Alpha models in our database.
Technical description: Parasite flame
Typical repair cost £150-300 (including labour)
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 E20 fault code
Click a model for the full fault code list and model-specific repair notes.
- C25 Xtraflame Repair: £120-250
- E-Tec Repair: £150-300
- E-Tec 24 Repair: £150-300
- E-Tec 28 Repair: £150-300
- E-Tec 33 Repair: £150-300
- E-Tec Plus Repair: £150-300
- E-Tec Plus 10 / 18 Repair: £120-350
- E-Tec Plus 24 Repair: £150-300
- E-Tec Plus 28 Repair: £150-300
- E-Tec Plus 33 Repair: £150-300
- E-Tec R Repair: £150-300
- Evoke Repair: £150-300
- Evoke 10 / 18 Repair: £120-350
- H25 Xtraflame Repair: £120-250
- Intec 28GS Repair: £120-250
- Intec 40GS2 Repair: £150-250
- Intec 50CS Repair: £120-250
- Intec2 25 28XE Repair: £120-250
- Intec2 30SE Repair: £150-300
- Pro Tec 24 Repair: £150-300
- Pro Tec Plus Repair: £150-300
Source
Alpha E20 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