Error Description

E4, E5, F1, F2, F3 aur F6 Error Codes generally indicate ki Temperature Sensor (Thermistor) mein Open Circuit, Short Circuit, ya Abnormal Resistance detect hui hai. Is wajah se Indoor ya Outdoor PCB sensor ki temperature reading receive nahi kar pati aur AC protection mode mein chala jata hai.

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Step 1: Safety First

✅ MCB OFF karein.

✅ Indoor aur Outdoor Unit ki power supply disconnect karein.

✅ Safety Gloves aur Digital Multimeter ka use karein.

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Step 2: Error Code Confirm Karein

Service Manual ya Display se confirm karein ki error kis sensor ka hai.

Typical Sensor Errors:

• F1 – Indoor Room Temperature Sensor
• F2 – Indoor Evaporator Coil Sensor
• F3 – Outdoor Ambient Temperature Sensor
• F6 – Outdoor Condenser Coil Sensor
• E4 / E5 – Discharge Pipe Sensor ya Outdoor Temperature Sensor Fault (Brand ke hisaab se alag ho sakta hai)

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Step 3: Sensor Connector Check Karein

PCB par sensor connector ko inspect karein.

Check karein:

• Loose Connector
• Half Inserted Connector
• Rust
• Water Damage
• Broken Lock
• Bent Pins

Connector ko dobara properly reconnect karein.

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Step 4: Wiring Inspection

Sensor wire ko poori length mein check karein.

Inspect for:

• Cut Wire
• Pinched Wire
• Burnt Wire
• Rat Bite Damage
• Open Circuit
• Short Circuit

Multimeter se continuity check karein.

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Step 5: Sensor Resistance Check Karein

Sensor ko PCB se disconnect karein.

Room Temperature (25°C) par resistance measure karein.

Common NTC Sensor Values:

• 5 kΩ @ 25°C
• 10 kΩ @ 25°C
• 15 kΩ @ 25°C
• 20 kΩ @ 25°C

Note: Hamesha manufacturer ke resistance chart se compare karein.

Agar resistance:

• 0 Ω → Short Circuit
• OL / Infinite → Open Circuit
• Chart se bahut alag → Sensor Defective

To sensor replace karein.

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Step 6: PCB Supply Voltage Check Karein

Sensor connector par PCB voltage check karein.

Normally:

• 3.3 VDC
• 5 VDC

Brand ke hisaab se voltage different ho sakti hai.

Agar voltage missing hai to PCB faulty ho sakti hai.

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Step 7: Sensor Position Check Karein

Ensure karein ki sensor:

• Proper clip mein laga ho
• Pipe ko touch kar raha ho (Pipe Sensor)
• Air flow ke saamne ho (Room Sensor)
• Insulation theek ho

Galat mounting se bhi error aa sakta hai.

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Step 8: Outdoor Unit Inspection

Outdoor Unit mein check karein:

• Condenser Coil Sensor
• Ambient Sensor
• Discharge Temperature Sensor

Saare connectors aur wiring secure honi chahiye.

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Step 9: PCB Inspection

Indoor aur Outdoor PCB ko visually inspect karein.

Check karein:

• Burn Marks
• Water Damage
• Carbon Deposits
• Loose Connectors
• Dry Solder Joints
• Damaged Sensor Circuit

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Step 10: Reset the AC

Power OFF karein.

5 minute wait karein.

Power ON karke error dobara check karein.

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Step 11: Perform Test Run

Cooling Mode mein AC start karein.

Observe karein:

✅ Sensor Reading Normal Hai?

✅ Compressor Start Ho Raha Hai?

✅ Indoor Fan Proper Chal Raha Hai?

✅ Outdoor Fan Proper Chal Raha Hai?

✅ Error Dubara Aa Raha Hai Ya Nahi?

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Possible Causes

• Faulty Temperature Sensor (NTC)
• Open Circuit Sensor Wire
• Short Circuit Sensor Wire
• Loose Sensor Connector
• Damaged PCB Sensor Circuit
• Water Damage on PCB
• Corroded Connector
• Incorrect Sensor Installation
• Defective Indoor PCB
• Defective Outdoor PCB

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Required Tools

• Digital Multimeter
• Clamp Meter
• Thermometer
• Screwdriver Set
• Continuity Tester
• Insulation Tester (Megger)
• Manufacturer Sensor Resistance Chart

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Pro Technician Tip

✅ Kisi bhi Temperature Sensor ko replace karne se pehle uski Resistance, PCB Supply Voltage, Connector Condition, aur Wiring Continuity ko zaroor check karein. Bahut baar E4, E5, F1, F2, F3 aur F6 Errors sirf loose connector, damaged wiring, ya corroded terminals ki wajah se aate hain. Accurate diagnosis se unnecessary sensor ya PCB replacement aur customer ka extra repair cost dono bachaya ja sakta hai.

Error Description

The E4, E5, F1, F2, F3, and F6 error codes generally indicate an Open Circuit, Short Circuit, or abnormal resistance in a temperature sensor (thermistor). As a result, the Indoor or Outdoor PCB cannot receive a valid temperature signal, and the air conditioner enters protection mode.

Step 1: Safety First

• Turn OFF the MCB (Main Circuit Breaker).

• Disconnect power to both the Indoor and Outdoor Units.

• Use safety gloves and a digital multimeter.

Step 2: Confirm the Error Code

Check the service manual or display to identify which sensor is affected.

Typical sensor-related errors:

• F1 – Indoor Room Temperature Sensor

• F2 – Indoor Evaporator Coil Sensor

• F3 – Outdoor Ambient Temperature Sensor

• F6 – Outdoor Condenser Coil Sensor

• E4 / E5 – Discharge Pipe Sensor or Outdoor Temperature Sensor fault (varies by brand)

Step 3: Check Sensor Connectors

Inspect the sensor connector on the PCB for:

• Loose connector

• Partially inserted connector

• Rust or corrosion

• Water damage

• Broken connector lock

• Bent pins

Reconnect the connector securely.

Step 4: Inspect the Wiring

Check the sensor wire along its entire length for:

• Cut wire

• Pinched wire

• Burnt wire

• Rodent damage

• Open circuit

• Short circuit

Use a multimeter to verify continuity.

Step 5: Check Sensor Resistance

Disconnect the sensor from the PCB and measure its resistance at 25°C (77°F).

Common NTC sensor values:

• 5 kΩ @ 25°C

• 10 kΩ @ 25°C

• 15 kΩ @ 25°C

• 20 kΩ @ 25°C

Always compare with the manufacturer's resistance chart.

Interpretation:

• 0 Ω → Short Circuit

• OL / Infinite → Open Circuit

• Far from chart value → Defective sensor

Replace the sensor if it fails the test.

Step 6: Check PCB Supply Voltage

Measure the voltage at the sensor connector on the PCB.

Typical values:

• 3.3 VDC

• 5 VDC

Voltage may vary by brand. If the supply voltage is missing, the PCB may be faulty.

Step 7: Verify Sensor Position

Ensure the sensor is:

• Properly clipped in place

• Touching the pipe (for pipe sensors)

• Located in the airflow path (for room sensors)

• Correctly insulated where required

Incorrect sensor mounting can also trigger these errors.

Step 8: Inspect the Outdoor Unit

Check the outdoor unit sensors:

• Condenser Coil Sensor

• Ambient Sensor

• Discharge Temperature Sensor

Make sure all connectors and wiring are secure.

Step 9: Inspect the PCB

Visually inspect the Indoor and Outdoor PCBs for:

• Burn marks

• Water damage

• Carbon deposits

• Loose connectors

• Dry solder joints

• Damaged sensor circuits

Step 10: Reset the AC

• Turn the power OFF.

• Wait approximately 5 minutes.

• Restore power and check whether the error has cleared.

Step 11: Perform a Test Run

Run the AC in Cooling Mode and verify:

• Sensor readings are normal

• Compressor starts properly

• Indoor fan operates correctly

• Outdoor fan operates correctly

• The error does not return

Possible Causes

• Faulty temperature sensor (NTC)

• Open-circuit sensor wiring

• Short-circuit sensor wiring

• Loose sensor connector

• Damaged PCB sensor circuit

• Water-damaged PCB

• Corroded connector

• Incorrect sensor installation

• Defective Indoor PCB

• Defective Outdoor PCB

Required Tools

• Digital Multimeter

• Clamp Meter

• Thermometer

• Screwdriver Set

• Continuity Tester

• Insulation Resistance Tester (Megger)

• Manufacturer's Sensor Resistance Chart

Professional Technician Tip

Before replacing any temperature sensor, always verify the sensor resistance, PCB supply voltage, connector condition, and wiring continuity. In many cases, E4, E5, F1, F2, F3, and F6 errors are caused by loose connectors, damaged wiring, or corroded terminals rather than a failed sensor. Accurate diagnosis helps avoid unnecessary sensor or PCB replacement and reduces repair costs for the customer.