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Error code reference

Daewoo Air Conditioner Error Code 3

Compressor, electrical parts of compressor, or gas leak error

Daewoo codesDaewoo air conditioner codes

Compressor, electrical parts of compressor, or gas leak error — indicated by ON lamp (Red LED) flashing with 0.5 second on/off pattern for 8 seconds.

First step from the service manual

Check voltage between L and Y of terminal block (indoor and outdoor unit); check connecting wire between indoor and outdoor unit; check relay RL1 on power PCB; check fixing of indoor coil thermistor; check gas leakage of the pipe.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What 3 means on a Daewoo air conditioner

Error code 3 on a Daewoo air conditioner signals a fault in the compressor circuit, the electrical components associated with the compressor, or a refrigerant gas leak. The system identifies this condition through the ON lamp (Red LED) flashing in a repeating 0.5-second on/off pattern for 8 seconds. This specific flash pattern distinguishes it from other fault codes and helps narrow diagnostics to the outdoor unit's core refrigeration and electrical systems.

The most common electrical cause involves a loss of proper voltage or signal between the indoor and outdoor units. Technicians should measure voltage between terminals L and Y on the terminal block, checking both the indoor and outdoor sides. A faulty or open relay RL1 on the power PCB can interrupt compressor operation entirely, and should be tested for continuity and proper switching behavior. Wiring faults in the connecting cable between the two units can also trigger this code if control signals are lost or corrupted.

Refrigerant loss is the other primary cause. When the system loses charge through a leak in the refrigerant circuit, suction pressure drops and the indoor coil thermistor may read abnormally low temperatures, mimicking an electrical fault. The indoor coil thermistor mounting should be checked for secure contact with the coil. All accessible refrigerant line connections, flare joints, and service valve packing should be inspected for signs of oil staining or leakage. A refrigerant leak requires recovery, leak repair, and proper recharge by a certified technician.

Source: manufacturer service documentation.

Common causes of 3

  1. 01

    Refrigerant gas leak

    Part replacement

    A leak in the refrigerant circuit reduces system pressure, causing abnormal coil temperatures and triggering the fault. Inspect all refrigerant line connections, flare fittings, and valve packing for oil staining, which often indicates a leak point.

  2. 02

    Faulty relay RL1 on the power PCB

    Part replacement

    Relay RL1 controls power delivery to the compressor circuit. If the relay fails to close or has damaged contacts, the compressor will not receive power and this error code will be triggered. Test the relay for proper switching and continuity.

  3. 03

    Incorrect voltage at terminal block (L to Y)

    Wiring / connection

    Low or absent voltage between terminals L and Y indicates a supply or wiring issue that prevents proper compressor operation. This should be measured at both the indoor and outdoor terminal blocks to isolate which section of the circuit is at fault.

  4. 04

    Damaged or faulty connecting wire between indoor and outdoor units

    Part replacement

    A broken, corroded, or improperly connected wire in the inter-unit cable can disrupt control signals and power, producing a compressor fault indication even if the compressor itself is undamaged. Inspect all wire terminals and check for continuity across the cable.

  5. 05

    Improperly fixed indoor coil thermistor

    Wiring / connection

    If the indoor coil thermistor is not seated firmly against the coil, it can read incorrect temperatures and cause the system to register a fault condition. Check that the thermistor clip or bracket is properly securing the sensor to the coil surface.

See the test procedure for each cause

Frequently asked questions about 3

What does 3 mean on a Daewoo air_conditioner?
Error code 3 on a Daewoo air conditioner indicates a fault related to the compressor, the electrical components of the compressor circuit, or a refrigerant gas leak. The system signals this code through the red ON lamp flashing in a 0.5-second on/off pattern for 8 seconds. This code points to the outdoor unit's refrigeration and power delivery systems as the areas requiring inspection.
How do I fix error code 3 on a Daewoo air conditioner?
Start by checking the voltage between terminals L and Y on the terminal block at both the indoor and outdoor units, and inspect the connecting wire between the two units for damage or loose connections. Test relay RL1 on the power PCB for proper operation, and verify that the indoor coil thermistor is firmly secured to the coil. If no electrical fault is found, inspect all refrigerant line connections and fittings for signs of a gas leak, as refrigerant recovery, repair, and recharge must be performed by a certified technician.
Is error code 3 on a Daewoo air conditioner dangerous?
A refrigerant leak, which is one potential cause of this error, can pose health risks in enclosed spaces and should be addressed promptly by a qualified technician. Electrical faults in the compressor circuit also carry a risk of damage to other components if the unit continues to operate. It is best to turn off the air conditioner and arrange for a professional inspection when this code appears.
How much does it cost to repair error code 3 on a Daewoo air conditioner?
Repair costs vary widely depending on the root cause. A simple wiring fix or thermistor reseating may cost relatively little in labor, while relay replacement on the power PCB typically runs in the range of $75 to $200 including parts and labor. A refrigerant leak repair combined with recharge can range from $150 to $500 or more depending on the leak location and the amount of refrigerant required.
Will resetting the unit clear error code 3 on a Daewoo air conditioner?
Resetting the unit may temporarily clear the fault display, but the code will return if the underlying problem has not been corrected. Because this error involves compressor circuitry or a potential refrigerant leak, a reset alone is not a fix. The root cause must be diagnosed and repaired to prevent recurring faults and potential damage to the compressor.

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