mypros+
Error code reference

Daewoo Air Conditioner Error Code 1 blink (0.5s interval, 8s cycle)

Indoor coil sensor open or short circuit; unit does not work.

Daewoo codesDaewoo air conditioner codes

Indoor coil sensor open or short circuit; unit does not work.

First step from the service manual

Check fixing of indoor coil thermistor.

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

MyPros+ Max

Get the full diagnostic procedure for 1 blink (0.5s interval, 8s cycle).

  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
  • Verified part numbers when replacement is required
Get the full procedure

$29/month · Cancel anytime · Or $9.95 3-day pass

What 1 blink (0.5s interval, 8s cycle) means on a Daewoo air conditioner

The 1 blink fault code on a Daewoo air conditioner, displayed in a 0.5-second interval pattern repeating on an 8-second cycle, signals a fault in the indoor coil thermistor circuit. This thermistor is a temperature-sensitive resistor mounted directly on or near the evaporator coil inside the indoor unit. The control board continuously monitors the resistance value from this sensor to regulate cooling cycles, prevent freeze-up, and protect the coil from damage. When the board detects a resistance reading that falls outside the expected operating range, it classifies the fault as either an open circuit (no continuity, indicating a broken wire or failed sensor) or a short circuit (near-zero resistance, indicating an internal sensor failure or wiring short to ground). In either condition, the unit shuts down completely and will not operate.

The indoor coil thermistor is a negative temperature coefficient (NTC) type, meaning its resistance decreases as temperature rises. A properly functioning sensor will show a predictable resistance curve across the coil's operating temperature range. When the sensor becomes disconnected from its mounting clip or plug, the circuit opens and the board reads an out-of-range high resistance. Conversely, if the sensor probe or wiring insulation is damaged and contacts a grounded metal surface, the circuit shorts and reads near-zero resistance. Both conditions trigger this fault and prevent operation.

The first diagnostic step is to inspect the physical mounting and connection of the indoor coil thermistor. A loose thermistor plug at the control board or a sensor that has slipped out of its clip on the coil is a common and easily corrected cause of this fault. If the wiring and connections are secure, the thermistor itself should be tested with a multimeter to confirm it is reading a plausible resistance value for the current ambient temperature. A sensor reading open or shorted must be replaced before the unit will resume normal operation.

Source: manufacturer service documentation.

Common causes of 1 blink (0.5s interval, 8s cycle)

  1. 01

    Loose or disconnected thermistor connector

    Wiring / connection

    The thermistor plug at the control board or the sensor clip on the coil may have worked loose over time, breaking the circuit. Visually inspecting and reseating the connector is the first step and often resolves the fault without part replacement.

  2. 02

    Failed indoor coil thermistor

    Part replacement

    The thermistor probe itself may have failed internally, causing it to read open or shorted regardless of temperature. Testing with a multimeter will show either no continuity or near-zero resistance when a mid-range value is expected.

  3. 03

    Damaged wiring harness

    Part replacement

    The wire running from the thermistor to the control board may be pinched, cut, or have degraded insulation that causes a short to the chassis. Inspect the full length of the harness for visible damage or bare conductors.

  4. 04

    Thermistor dislodged from coil clip

    Wiring / connection

    If the sensor has slipped out of its mounting clip on the evaporator coil, it is no longer reading coil temperature accurately and the circuit reading will be erratic or out of range. Reseating the sensor in its correct clip position may restore normal operation.

  5. 05

    Faulty indoor control board

    Part replacement

    If the thermistor and all wiring test correctly but the fault persists, the input circuit on the control board itself may be damaged. This is the least common cause and should only be suspected after the sensor and wiring are confirmed good.

See the test procedure for each cause

Frequently asked questions about 1 blink (0.5s interval, 8s cycle)

What does 1 blink (0.5s interval, 8s cycle) mean on a Daewoo air_conditioner?
This blink pattern indicates an open or short circuit fault in the indoor coil thermistor, which is the temperature sensor mounted on the evaporator coil inside the indoor unit. The control board cannot get a valid reading from the sensor, so the unit shuts down completely to prevent damage. The fault points to either a disconnected sensor plug, a damaged wiring harness, or a failed thermistor probe.
Can I fix the 1 blink error on my Daewoo air conditioner myself?
If the cause is a loose connector or a thermistor that has slipped out of its mounting clip, a knowledgeable DIYer can often resolve the fault by reopening the indoor unit cover, reseating the plug, and securing the sensor back in its clip. However, if the thermistor has failed electrically or the wiring is damaged, replacing components inside the unit is better suited to a qualified technician. Always disconnect power to the unit before opening any panels.
Is it safe to keep running my Daewoo air conditioner when it shows this error?
The unit will not run when this fault is active, so there is no immediate safety risk from continued operation. The shutdown is a protective response by the control board. Do not attempt to bypass the fault, as the coil thermistor provides important freeze protection and operating without it could damage the evaporator coil or compressor over time.
Will resetting my Daewoo air conditioner clear this error code?
A power reset may temporarily clear the displayed fault, but if the underlying problem with the thermistor or its wiring has not been corrected, the fault will return as soon as the control board re-reads the sensor circuit. A reset alone is not a fix. The sensor, connector, and wiring must be inspected and the faulty component repaired or replaced before the unit will operate reliably.
How much does it cost to repair a Daewoo air conditioner indoor coil sensor fault?
If only the thermistor probe needs replacement, parts costs are generally in the range of $10 to $40 depending on the specific unit model, with labor adding $75 to $150 for a service call in most markets. If the control board is found to be faulty, parts costs rise considerably, typically $80 to $200 or more. Getting a diagnostic visit from a qualified technician will give you a more accurate estimate for your specific situation.

Related Daewoo air conditioner codes

All Daewoo air conditioner codes
View all 45 Daewoo air conditioner codes

78,000+ service manuals · 160,000+ error codes · 55+ brands

Get Started

$29/month · Cancel anytime · Or $9.95 3-day pass