| Code | Meaning | Models |
|---|---|---|
| _St | Autostop | New |
| _CL | Call for service | New |
| A01 | Ignition failure flame not sensed – internal fault | New |
| A02 | Limit thermostat fault | New |
| A03 | Fan fault | New |
| A04 | Insufficient system water pressure | New |
| A06 | Domestic how water (DHW) thermistor fault | New |
| A07 | Primary flow thermistor fault – temperature of water is too high. | New |
| A08 | Return thermistor fault – water temperature too high. | New |
| A09 | Flue thermistor or ßue thermistor counter fault. | New |
| A11 | False flame | New |
| A77 | Low temperature thermostat fault | New |
| ADJ | Calibration | New |
| ACO | Service operation | New |
| N/A | Flame on | New |
| P | Preheating function active | New |
| P Blinking | Preheating function running | New |
| Hours | Stand-by | New |
| - | Off | New |
| 01 | Failure to ignite | New |
| 02 | Overheat | New |
| 03 | Problem with fan/flue | New |
| 04 | Insufficient water pressure | New |
| 05 | Reset as described for code 01 | New |
| 06 | Hot water thermistor open circuit | New |
| 07 | Primary thermistor open circuit | New |
| E10 | Flame lockout | Evolve Combi |
| E011 | Extraneous flame | Evolve Combi |
| E020 | Limit thermostat | Evolve Combi |
| E030 | Fan fault | Evolve Combi |
| E040 | Water transducer – check system water pressure | Evolve Combi |
| E041 | Water transducer – check system water pressure | Evolve Combi |
| E042 | Water transducer fault | Evolve Combi |
| E060 | Domestic hot water probe fault | Evolve Combi |
| 4070 | Fault flow sensor over temperature – flow sensor flow/return line probe differential alarm | Evolve Combi |
| E077 | Main zone water thermostat | Evolve Combi |
| E080 | Error with return line probe – over temperature outlet or differential alarm | Evolve Combi |
| E090 | Flue gases over temperature probe | Evolve Combi |
| E091 | Clean primary heat exchanger | Evolve Combi |
| - | Water pressure low | Evolve Combi |
| - | Water pressure high | Evolve Combi |
| - | Boiler board communication lost | Evolve Combi |
| - | BUS 485 communication lost | Evolve Combi |
| E021, E022, E023, E024, E067. E088, E097 | Iono alarm | Evolve Combi |
| E085, E094, E095 | Combustion fault/high CO | Evolve Combi |
| E058 | Main voltage error | Evolve Combi |
| E065 | Current modulation alarm | Evolve Combi |
| E086 | Obstruction fumes alarm | Evolve Combi |
| AL10, AL20, AL21, AL26, AL28, AL34 | Try resetting the boiler, if the fault reoccurs you need to contact a heating engineer. | Mynute |
| AL40 | Check the systemÕs pressure and refill if necessary. Reset the boiler, if the fault reoccurs then you need to contact a heating engineer. | Mynute |
| AL41 | Check system pressure – refill if necessary. If fault reoccurs, contact a heating engineer. | Mynute |
| AL52, AL55, AL60, AL71,AL73, AL74, AL79 | Contact a heating engineer. | Mynute |
| AL74, AL79 | Reset the boiler. If the fault reoccurs, contact a heating engineer. | Mynute |
Gas work stays with a Gas Safe registered engineer. Some codes only apply to a named range — check the model column.