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Error code reference

Daewoo Air Conditioner Error Code E3

Compressor or electrical parts of compressor error

Daewoo codesDaewoo air conditioner codes

Compressor or electrical parts of compressor error - indoor coil temperature does not change by +/-2°C within 5 minutes of compressor start (ON lamp blinks 2 times pattern, 0.5s interval).

First step from the service manual

Check voltage between L and Y of terminal block; check connecting wire between indoor and outdoor unit; check relay RL1 on power PCB.

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

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What E3 means on a Daewoo air conditioner

The E3 error code on a Daewoo air conditioner indicates a compressor or compressor electrical parts fault. The control system monitors indoor coil temperature immediately after the compressor starts. If the indoor coil temperature fails to change by at least plus or minus 2 degrees Celsius within 5 minutes of compressor activation, the unit triggers E3 and halts operation. This temperature change is the expected result of refrigerant circulation driven by the compressor, so a lack of thermal shift at the indoor coil points to the compressor failing to run, failing to pump refrigerant, or not receiving proper electrical signals from the indoor unit.

The diagnostic process begins at the terminal block connecting the indoor and outdoor units. Technicians should measure voltage between terminals L and Y on the terminal block to confirm the outdoor unit is receiving the correct control signal. If voltage is present and correct, attention shifts to the connecting wiring between indoor and outdoor units for breaks, corrosion, or loose connections. Relay RL1 on the power PCB is also a primary suspect, as this relay is responsible for switching power to the compressor circuit. A failed or sticking relay will prevent the compressor from energizing even when the control board sends the correct signal.

Additional causes can include a seized or failed compressor motor, a faulty run capacitor that prevents the compressor from reaching operating speed, or low refrigerant charge that inhibits heat exchange at the indoor coil. Each of these conditions results in the same observable outcome: the indoor coil temperature remains static after startup, triggering the E3 fault. The ON lamp blinks in a repeating 2-blink pattern with 0.5-second intervals between blinks to indicate this specific fault code.

Source: manufacturer service documentation.

Common causes of E3

  1. 01

    Faulty relay RL1 on power PCB

    Part replacement

    Relay RL1 controls power switching to the compressor circuit. If it has failed open or is not engaging, the compressor will not receive power regardless of the control signal, and coil temperature will not change. Check for continuity and switching function on RL1.

  2. 02

    Wiring fault between indoor and outdoor unit

    Wiring / connection

    Broken, corroded, or loose connecting wires between the indoor and outdoor units can interrupt the control signal or power path to the compressor. Inspect all wiring and terminal connections for visible damage, oxidation, or loose terminals.

  3. 03

    Incorrect or missing voltage at terminal block L and Y

    Wiring / connection

    If voltage between terminals L and Y is absent or out of specification, the outdoor unit is not receiving the correct signal to activate the compressor. This can point to a failed control board, blown fuse, or wiring issue on the indoor side.

  4. 04

    Failed or seized compressor

    Part replacement

    A compressor that is mechanically seized or has a burned winding will not pump refrigerant even when it receives full electrical power. This results in no coil temperature change and triggers E3. Confirm by checking compressor windings for correct resistance and listening for startup sounds.

  5. 05

    Low refrigerant charge

    Part replacement

    Insufficient refrigerant in the system means the compressor may run but cannot produce the expected temperature change at the indoor coil within the 5-minute window. A refrigerant leak should be suspected if electrical components check out correctly.

See the test procedure for each cause

Frequently asked questions about E3

What does E3 mean on a Daewoo air_conditioner?
E3 on a Daewoo air conditioner signals a compressor or compressor electrical parts error. The unit measures indoor coil temperature after startup and expects a change of at least plus or minus 2 degrees Celsius within 5 minutes. If that change does not occur, the system triggers E3 and displays the fault as the ON lamp blinking twice repeatedly with 0.5-second intervals. The compressor is either not running, not receiving power, or the refrigerant system is not functioning correctly.
Can I fix an E3 error on my Daewoo air conditioner myself?
Some basic checks are accessible to a knowledgeable DIYer, such as inspecting the wiring connections between the indoor and outdoor units for loose or corroded terminals. However, diagnosing relay RL1 on the power PCB, measuring terminal block voltage, and evaluating the compressor itself require electrical test equipment and some technical skill. Any work involving refrigerant must be performed by a certified technician.
Is it safe to keep running my Daewoo air conditioner when E3 is displayed?
No. The E3 error causes the unit to shut down as a protective measure, and attempting to override or repeatedly restart it without diagnosing the root cause can cause further damage to the compressor or electrical components. Leave the unit off until the fault is diagnosed and corrected.
Will resetting my Daewoo air conditioner clear the E3 error?
A power reset may temporarily clear the E3 display, but the error will return if the underlying fault is not repaired. The control system re-evaluates coil temperature every time the compressor starts, so if the compressor, relay, or wiring issue is still present, E3 will be triggered again within 5 minutes of the next startup.
How much does it cost to repair a Daewoo E3 error?
Repair costs vary widely depending on the cause. Replacing relay RL1 on the power PCB is typically a lower-cost repair, often in the range of $75 to $200 including labor. A failed compressor is the most expensive scenario, with replacement costs commonly ranging from $400 to $900 or more depending on the unit size and parts availability. A refrigerant recharge, if a leak is found and repaired, generally falls in the $150 to $400 range.

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