LineMini-Split Heat Pump Series
41codes
/
Fault

E0Overcurrent Protection of Indoor Unit

What it means

The main control panel detects that the system's working current has exceeded the upper protection limit. The unit stops running and displays E0.

Inspection path

1Current transformer→2Power line→3Compressor line→4Connector assembly

Diagnostic procedure

  1. For fixed-frequency models: confirm the live wire passes through the current transformer correctly. If not, reroute the wire and reboot.
  2. Use a current clamp to measure working current and compare against the nameplate range. If current is within range, the current transformer itself may be faulty — replace the indoor unit main control panel.
  3. Measure supply voltage and confirm it falls within the normal operating range. If abnormal, investigate local grid stability.
  4. If working current exceeds the nameplate range and supply voltage is normal, the system may be blocked or the unit overloaded. Inspect based on actual site conditions.

Tools

  • Current clamp
  • Multimeter

Frequent parts

  • Indoor unit main control panel
  • Power line
  • Compressor
SafetyDisconnect power at the breaker before opening any access panel. DC bus capacitors retain charge for up to 5 minutes after disconnect - verify with a meter before touching live components.
Sensor Reference6

Recirculated

20 kΩ @ 25°C
Too-high resistanceIncorrect back temperature value affects electronic expansion valve adjustment and four-way valve position confirmation during heating.
Too-low resistanceIncorrect back temperature value affects electronic expansion valve adjustment and four-way valve position confirmation during heating.
TriggersFARecirculated Sensor Error

External temperature

15 kΩ @ 25°C
Too-high resistanceDetected outdoor temperature reads lower than actual, causing incorrect temperature-based control decisions.
Too-low resistanceDetected outdoor temperature reads higher than actual, causing incorrect temperature-based control decisions.
TriggersF6External Temperature Sensor Error

Exhaust

50 kΩ @ 25°C
Too-high resistanceDetected exhaust temperature reads lower than actual. The system may fail to activate protection when exhaust temperature is genuinely dangerous.
Too-low resistanceDetected exhaust temperature reads higher than actual. The unit enters high exhaust temperature protection frequently, compressor frequency threshold rises, leading to unwanted shutdowns. Example: installing a 20KΩ coil sensor in place of the 50KΩ exhaust sensor produces this behavior.
TriggersP5Exhaust ProtectionF4Exhaust Sensor Error

Internal coil

20 kΩ @ 25°C
Too-high resistanceDetected temperature reads lower than actual. May cause high-pressure cold-blast protection during heating or frequent anti-freezing protection during cooling.
Too-low resistanceDetected temperature reads higher than actual. May cause frequent overheat protection during heating or overload protection during cooling.
TriggersP7Anti-Freezing Protection in Refrigeration ModeP6Indoor High Temperature ProtectionE3Internal Coil Sensor Error

External coil

20 kΩ @ 25°C
Too-high resistanceDetected temperature reads lower than actual. May cause frequent entry into defrost mode, illusory defrost cycles, or protection errors during cooling.
Too-low resistanceDetected temperature reads higher than actual. May cause defrost failures during heating or protection activation during cooling.
TriggersP4Refrigeration Overload ProtectionE2External Coil Sensor Error

Internal temperature

15 kΩ @ 25°C
Too-high resistanceDetected temperature reads lower than actual. May cause shutdown errors in heating mode or startup failures in cooling mode.
Too-low resistanceDetected temperature reads higher than actual. May cause startup errors in heating mode or shutdown failures in cooling mode.
TriggersE1Internal Temperature Sensor Error