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Error code reference

Daewoo Air Conditioner Error Code 2 blinks (ON lamp, 0.5s pattern)

Outdoor coil sensor open or short, compressor or electrical parts of compressor error, or gas leak

Daewoo codesDaewoo air conditioner codes

Outdoor coil sensor open or short, compressor or electrical parts of compressor error, or gas leak — unit continues working.

First step from the service manual

Check voltage between L and Y of terminal block (indoor and outdoor unit); check connecting wire; check relay RL1 on power PCB; check compressor; check for gas leakage.

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

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  • Wiring diagram references and connector pinouts from the OEM service manual
  • Verified part numbers when replacement is required
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What 2 blinks (ON lamp, 0.5s pattern) means on a Daewoo air conditioner

The 2-blink ON lamp fault code on a Daewoo air conditioner signals a group of related issues involving the outdoor circuit: an open or shorted outdoor coil sensor (thermistor), a compressor fault or electrical failure within the compressor circuit, or a refrigerant gas leak. The 0.5-second blink pattern is how the indoor unit's ON indicator communicates this fault group. Importantly, the unit continues operating despite the active fault, meaning the system has not fully shut down but is flagging a condition that needs attention before it causes further damage.

The outdoor coil sensor is a thermistor that monitors refrigerant coil temperature. If the sensor's resistance falls outside the expected range due to a failed sensor, damaged wiring, or a loose connector, the control board interprets this as an open or short condition. Compressor faults can originate from winding failures, starting relay or capacitor problems, or loss of power to the compressor circuit. Relay RL1 on the power PCB is a key component in the compressor start circuit and should be checked for proper switching function and contact integrity.

A refrigerant gas leak compounds all of these symptoms because low refrigerant causes abnormal coil temperatures, which can look similar to a sensor fault and also stresses the compressor. Diagnostics begin at the terminal block by measuring voltage between terminals L and Y on both the indoor and outdoor units to confirm proper power delivery. From there, the connecting wire between units, relay RL1, the compressor itself, and refrigerant charge level all require systematic inspection.

Source: manufacturer service documentation.

Common causes of 2 blinks (ON lamp, 0.5s pattern)

  1. 01

    Outdoor coil sensor (thermistor) failure

    Part replacement

    The outdoor coil thermistor may have drifted out of its normal resistance range or developed an open/short circuit due to age or moisture ingress. Inspect the sensor connector and measure thermistor resistance to confirm.

  2. 02

    Refrigerant gas leak

    Part replacement

    A low refrigerant charge causes abnormal coil temperatures that can trigger sensor-related faults and stress the compressor. Check system pressure and inspect the refrigerant lines and connections for signs of leakage.

  3. 03

    Relay RL1 fault on the power PCB

    Part replacement

    Relay RL1 controls the compressor circuit and can fail due to contact wear or coil burnout. Check the relay for proper switching operation and replace the PCB or relay if it is not activating correctly.

  4. 04

    Compressor electrical fault

    Part replacement

    Internal compressor winding failures or a faulty starting capacitor can produce a compressor error under this fault code. Measure compressor winding resistance and inspect the capacitor for bulging or incorrect capacitance values.

  5. 05

    Damaged or loose connecting wiring between indoor and outdoor units

    Wiring / connection

    Broken, corroded, or improperly secured wires between the indoor and outdoor terminal blocks can cause erratic voltage readings at the L and Y terminals. Inspect all connecting wires and ensure secure termination at both ends.

See the test procedure for each cause

Frequently asked questions about 2 blinks (ON lamp, 0.5s pattern)

What does 2 blinks (ON lamp, 0.5s pattern) mean on a Daewoo air_conditioner?
This blink pattern indicates one of three related faults in the outdoor unit: an open or shorted outdoor coil sensor, a compressor or compressor electrical component fault, or a refrigerant gas leak. The system continues to run while this code is active, but the underlying issue requires prompt diagnosis. Checking voltage at the L and Y terminals of the indoor and outdoor terminal blocks is the recommended starting point.
Can I fix the 2-blink error on my Daewoo air conditioner myself?
Some steps, such as inspecting connecting wires for damage and checking that all terminal connections are secure, can be done by a knowledgeable DIYer. However, checking refrigerant charge, testing relay RL1 on the power PCB, and diagnosing compressor faults require proper tools and in most regions require a licensed technician for any refrigerant handling. Attempting repairs on live electrical components without proper training is hazardous.
Is it safe to keep running my air conditioner while this error is active?
The unit is designed to continue operating when this code is present, but running the system with a refrigerant leak or a failing compressor can cause permanent compressor damage. If the unit is cooling poorly, making unusual noises, or if you suspect a refrigerant leak, shut the system off and have it inspected promptly. Continued operation under these conditions increases the risk of a more costly repair.
Will resetting the unit clear the 2-blink error code?
A power reset may temporarily clear the displayed fault, but if the underlying fault condition still exists, the code will return once the unit resumes operation. Resetting without addressing the root cause does not fix the problem and may delay necessary repairs. The fault should be diagnosed and corrected before relying on the system for continued use.
How much does it cost to repair the 2-blink fault on a Daewoo air conditioner?
Repair costs vary significantly depending on which component has failed. Replacing a thermistor sensor is typically a lower-cost repair, while power PCB replacement or compressor service is more expensive. If a refrigerant leak is involved, the cost includes both leak repair and refrigerant recharge. In general, expect diagnostic and repair costs to range from around $75 to $600 or more depending on the fault and local labor rates.

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