| F.61 | Gas valve activation error. | The valve driver on the PCB does not switch/read the valve correctly, and the equipment locks out for safety. Check voltage/signal from PCB to the valve and harness; if the valve closes/operates well in a direct test, the cause is the PCB. |
| F.62 | Delay in gas valve disconnection. | Valve control stage on the PCB remains 'stuck' or sends a closing command out of time. Check the signal from the PCB to the coils and the valve's tightness/closure; if the valve functions correctly in the test and the fault persists, the PCB is the cause. |
| F.63 | EEPROM fault (defective electronics). | Corruption/damage of the EEPROM in the PCB causes the control not to start or to freeze. Check reprogramming/parameterization if applicable; if not possible or it fails again, replace the PCB ref. 0020035443. |
| F.64 | Fault in the electronics/sensors (NTC) or defective electronics. | The ADC input/measurement stage on the PCB interprets short/incorrect values even though the NTCs are fine. Rule out NTC/wiring with resistance measurement; if they are correct, the PCB is damaged. |
| F.65 | Temperature of the electronics too high. | The PCB detects overheating (internal sensor or damaged electronics). Check the actual temperature in the electronic box/ventilation and external causes; if it is normal and still shows F.65, the PCB is defective. |
| F.67 | Fault: electronics/flame (flame signal not plausible). | The detection stage in the PCB interprets 0/5 V or an unlikely ionisation signal due to electronic fault. Check electrode/wiring/flame guard; if all OK and it persists, the defect is in the PCB. |
| F.70 | Invalid appliance code (DSN)/incorrect parameterization. | After replacing the display and PCB simultaneously or using an incorrect coding resistor, the PCB remains without a valid DSN. Verify/adjust the DSN and coding resistor according to the service manual; if it cannot be parameterized, replace with the correct PCB. |
