What you find on this page:
D2CND Combi Gas Boiler Error Codes
| Fault Code | Possible Cause |
| 10-64 | Gas valve circuit error, try resetting boiler |
| 10-65 | Gas valve current fault, try resetting the boiler |
| 11-64 | Ignition error – possible fault with valve on the gas line due to it being open. Try resetting the boiler after the third unsuccessful ignition. |
| 11-65 | Flame stabilisation error – wait for the boiler ignition trial |
| 11-66 | Flame Signal loss in safety time – try to reset the boiler after 3rd unsuccessful ignition |
| 11-67 | Flame loss during operation. This is a temporary error, wait for the boiler to re-ignite. |
| 12-64 | Ion control deviation is too big – try resetting the boiler |
| 12-65 | Ignition scott actuators error – try resetting the boiler |
| 12-66 | Ion base value lower than the upper factory limit, try resetting the boiler |
| 12-67 | Ion base value exceeds the upper factory limit – try resetting the boiler |
| 12-68 | Ion base value differs from the previous value – try resetting the boiler |
| 12-69 | Offset adaptation at limit |
| 13-64 / 13-65 | Fan speed error – try resetting the boiler |
| 16-64 | Flue temperature signals overheating, the flue gas discharge path needs checking. Try resetting the boiler |
| 1J-64 | High limit thermostat signalising overheating. Check the valve of the radiators in the heating, check if the Combi boiler water pressure is low, if it is then the heating circuit needs filling with water |
| 80-01 | Return temperature sensor error – reset the boiler |
| 81-01 | Flow temperature sensor error – try resetting the boiler |
| 81-65 | Domestic hot water (DHW) temperature sensor error. The boiler will continue in operation but solar sensor has an error . |
| 8A-46 | Freeze protection – the boiler won’t operate if flow temperature sensor reads a value that is less than 1°c |
| 8H-65 | Flow temperature steep rise – the radiator valves may not be open enough to circulate water |
| E1-64 | Flame detected before burner operation – try resetting the boiler |
| E1-65 | Internal SCOT system error. Perform reset if needed |
| E1-66 | Calibration condition error, wait for burner to restart |
| E1-67 | Missing calibration – try resetting the boiler |
| E1-68 | Ion base value is outside the factory limits or saved incorrectly – try resetting the boiler |
| E1-69 / E1-70 | Parameter CRC fault – try resetting the boiler |
| E1-71 | EK lockout failure – this is a permanent error |
| E1-72 | SCOT flame amplifier – reset the boiler |
| E1-73 | Printed circuit board (PCB) error – try resetting the boiler |
| H9-01 | Outside sensor fault – try resetting the boiler |
| HC-01 | Domestic hot water (DHW) temperature sensor error. The boiler will continue to operate but you need to contact a heating engineer |
| HJ-08 | High system pressure – the boiler needs to discharge water down to 0.8 bar |
| HJ-09 | Low system pressure – increase the system pressure to 0.8 bar |
| HJ-10 | Water pressure sensor fault |
| J6-01 | Flow temperature sensor overheating due to a blocking fault or a lockout error – the valves of the radiator heating circuit may have an issue or the water pressure is low and needs filling |
| J6-20 | Return temperature sensor overheating due to a blocking fault or a lockout error – try resetting the boiler |
| J6-21 | Return temperature is higher than flow temperature. Burner operates itself after a small amount of time but if the problem repeats you need to contact a heating engineer |
| JJ-64 | Supply voltage is below low limit |
| U2-01 | Supply voltage is above high limit, your boiler should continue to operate but you need to contact a heating engineer |
| U4-65 | OpenTherm room thermostat connection is defective – your boiler will continue to operation but the thermostat is out of operation |
| U4-66 | CAN-bus timeout |
| U4-67 | Remote reset supervision, switch off the power at the mains – if problem repeats contact a heating engineer |
| UA-64 | Blocking during boiler chip card (BBC) update |
| UA-65 | Printed circuit board (PCB) requires a boiler chip card (BCC) update |
| UA-66 | Boiler chip card ID (BCC-iD) of internal Electrically Erasable Programmable Read-Only Memory (EEPROM) is inconsistent |
| UA-67 | Boiler chip card (BCC) is missing |
Error Code HJ-08
If you are seeing the error code HJ-08 this could be due to a high system pressure. To resolve this issue you need to discharge the water down to 0.8 bar. As well as this, you should also bleed your radiators.
