Complete guide to E-TEC, Evoke, CD, InTec series fault codes with troubleshooting advice
Alpha boilers use E-codes for most error displays. Here is the complete list of all Alpha error codes:
| Code | Meaning | Quick Fix | DIY? |
|---|---|---|---|
| E01 | Ignition failure | Check gas supply, thaw frozen condensate pipe, reset | Partial |
| E02 | Flame loss during operation | Check gas supply, reset boiler | Partial |
| E03 | Overheat protection activated | Let boiler cool, check radiators are on, bleed system | Partial |
| E04 | Low water pressure | Top up pressure using filling loop to 1.0-1.5 bar | Yes |
| E05 | Flow sensor fault | Reset boiler | No |
| E06 | Return sensor fault | Reset boiler | No |
| E07 | DHW sensor fault | Reset boiler | No |
| E08 | Outside sensor fault | Reset boiler, check sensor connection | No |
| E09 | PCB communication fault | Reset boiler | No |
| E10 | Low water pressure | Top up pressure using filling loop to 1.0-1.5 bar | Yes |
| E28 | Flue thermistor fault | Reset boiler, check flue terminal is clear | No |
| E34 | Fan speed fault | Reset boiler, check flue is not blocked | No |
| E35 | False flame detection | Do NOT repeatedly reset - call engineer immediately | No |
| E41 | Flow/return difference too great | Check system circulation, bleed radiators | Partial |
| E42 | Flow temperature rising too quickly | Check pump, check system for blockages | No |
| E50 | DHW temperature sensor fault | Reset boiler | No |
| E53 | PCB fault | Reset boiler | No |
| E54 | Gas valve fault | Reset boiler | No |
| E55 | Modulating gas valve fault | Reset boiler | No |
| E96 | Antifreeze protection activated | Increase heating setpoint | Yes |
| E97 | Pump blocked | Reset boiler, pump may need freeing | No |
| E98 | Diverter valve fault | Reset boiler | No |
| E99 | Internal communication fault | Reset boiler | No |
Our Gas Safe engineers service all Alpha models across Harrow and London.