Fault Codes & Troubleshooting
| LED Fault Indicator | Code Meaning | Possible Cause |
|---|---|---|
| E1* | False flame, residual flame, or ignition failure | Flame signal detected at startup, flame signal detected after combustion stops, or no flame detected after ignition. |
| E2* | Overheat fault | Temperature > 90°C; overheat relay disconnected. |
| E3* | Flue air pressure fault | Air pressure switch or fan abnormality. |
| E4* | Water flow or pressure fault | Water flow switch or water pressure switch abnormality. |
| E5 | Valve voltage fault | Voltage detected before startup or loose wiring. |
| E6* | Hot water NTC fault | Hot water NTC open circuit or short circuit. |
| E7* | Heating NTC fault | Heating NTC open circuit or short circuit. |
| E0* | Anti-freezing protection | When hot water NTC < 2°C, the unit stops operating. When heating NTC < 4°C, the unit enters operation mode. |
| EB* | Flue temperature fault | Flue temperature too high. |
| EL* | Condensate fault | Condensate pipe blocked. |
| EU* | Communication fault | Electromagnetic interference. |
Fault Code: “E0”
- Code Meaning: Heat dissipation water pipe temperature ≤ 2°C
- Possible Cause: Anti-freezing protection activated
- Solution: The system will stop all operation and display “E0”. The fault will clear automatically once the temperature returns to normal. When the heating NTC temperature is below 4°C, the unit enters anti-freezing operation mode.
Fault Code: “E1”
- Code Meaning: No flame detected after startup or abnormal residual flame signal
- Possible Cause: Ignition failure or false flame signal detection
- Solution: Turn the unit off and restart it. If the fault remains, contact qualified after-sales service personnel.
Fault Code: “E2”
- Code Meaning: Overheat protection
- Possible Cause: Temperature too high (> 90°C)
- Solution: Check whether the system pipeline or filter is blocked, then restart the unit. If the fault occurs frequently, contact qualified service personnel.
Fault Code: “E3”
- Code Meaning: Air pressure switch fault
- Possible Cause: Air pressure switch not closed or fan abnormality
- Solution: Check whether the flue is blocked. It is recommended to have the fan system inspected by qualified after-sales service personnel.
Fault Code: “E4”
- Code Meaning: Water flow or pressure switch abnormality
- Possible Cause: Low water pressure or poor water flow
- Solution: Check the water inlet and filter screen, and make sure the water pressure is above 1 bar. If the fault remains, contact qualified service personnel.
Fault Code: “E6”
- Code Meaning: Hot water temperature sensor fault
- Possible Cause: Hot water NTC open circuit or short circuit
- Solution: Contact qualified after-sales service personnel.
Fault Code: “E7”
- Code Meaning: Heating temperature sensor fault
- Possible Cause: Heating NTC open circuit or short circuit
- Solution: Contact qualified after-sales service personnel.
Fault Code: “EA”
- Code Meaning: Temperature exceeds 90°C
- Possible Cause: Hot water temperature too high
- Solution: Troubleshooting for this fault is the same as “E2”.