Line Mini-Split Heat Pump Series
41 codes
/
Fault

F6 External Temperature Sensor Error

LED

What it means

The main external control panel detected a short circuit or open circuit condition on the external temperature sensor.

Special attention Standard resistance for most external temperature sensors is 15KΩ at 25°C. Sensor resistance decreases as temperature increases and increases as temperature decreases. Using an incorrect sensor causes wrong outdoor temperature readings and incorrect control decisions.

Inspection path

1 Sensor → 2 Sensor wire → 3 Connectors → 4 Main external control panel

Diagnostic procedure

  1. Measure sensor resistance. It should be approximately 15KΩ at 25°C. Check for short circuit or open circuit.
  2. Inspect the sensor wire for breaks or damage.
  3. Verify all terminal connectors are firmly seated. Check for loose solder joints between the terminal and the main control panel.
  4. Check whether the sensor has moisture damage.
  5. If no standard sensor is available, swap in a nearby sensor temporarily. If the error clears, replace the original sensor. If the error persists, replace the main external control panel.

Tools

  • Multimeter
  • 15KΩ standard sensor (25°C)

Frequent parts

  • External temperature sensor
  • Main external control panel

Sensors referenced

Safety Disconnect 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 Reference 6

Internal temperature

15 kΩ @ 25°C
Too-high resistance Detected temperature reads lower than actual. May cause shutdown errors in heating mode or startup failures in cooling mode.
Too-low resistance Detected temperature reads higher than actual. May cause startup errors in heating mode or shutdown failures in cooling mode.
Triggers E1 Internal Temperature Sensor Error

External coil

20 kΩ @ 25°C
Too-high resistance Detected temperature reads lower than actual. May cause frequent entry into defrost mode, illusory defrost cycles, or protection errors during cooling.
Too-low resistance Detected temperature reads higher than actual. May cause defrost failures during heating or protection activation during cooling.
Triggers P4 Refrigeration Overload Protection E2 External Coil Sensor Error

Internal coil

20 kΩ @ 25°C
Too-high resistance Detected temperature reads lower than actual. May cause high-pressure cold-blast protection during heating or frequent anti-freezing protection during cooling.
Too-low resistance Detected temperature reads higher than actual. May cause frequent overheat protection during heating or overload protection during cooling.
Triggers P6 Indoor High Temperature Protection P7 Anti-Freezing Protection in Refrigeration Mode E3 Internal Coil Sensor Error

Exhaust

50 kΩ @ 25°C
Too-high resistance Detected exhaust temperature reads lower than actual. The system may fail to activate protection when exhaust temperature is genuinely dangerous.
Too-low resistance Detected 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.
Triggers F4 Exhaust Sensor Error P5 Exhaust Protection

External temperature

15 kΩ @ 25°C
Too-high resistance Detected outdoor temperature reads lower than actual, causing incorrect temperature-based control decisions.
Too-low resistance Detected outdoor temperature reads higher than actual, causing incorrect temperature-based control decisions.
Triggers F6 External Temperature Sensor Error

Recirculated

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