mypros+
Error code reference

Samsung Air Conditioner Error Code E165

No change of EVAP OUT temperature during piping check.

Samsung codesSamsung air conditioner codes

No change of EVAP OUT temperature during piping check.

First step from the service manual

Check indoor unit address matches MCU; check EEV connection to PCB.

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 E165.

  • 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 E165 means on a Samsung air conditioner

Error code E165 on a Samsung air conditioner indicates that no temperature change was detected at the evaporator outlet (EVAP OUT) sensor during a piping check sequence. The piping check is a diagnostic routine the system runs to verify refrigerant flow and heat exchange are functioning correctly. During this check, the system expects the evaporator outlet temperature to rise or fall by a measurable amount as refrigerant circulates. When the sensor reading remains flat, the control board flags E165 because it cannot confirm that refrigerant is actually moving through the indoor unit's evaporator coil.

The two most likely starting points for diagnosis are the indoor unit address configuration and the electronic expansion valve (EEV). If the indoor unit address does not match what the main control unit (MCU) expects, the piping check command may never actually reach the correct unit, resulting in no temperature response. The EEV controls refrigerant flow into the evaporator, so if its wiring harness is disconnected, damaged, or improperly seated at the PCB, the valve will not open during the check and refrigerant will not flow, leaving the EVAP OUT sensor reading unchanged.

Additional causes can include a faulty EVAP OUT thermistor that is stuck reporting a fixed value, wiring faults between the sensor and the indoor PCB, or a defective EEV coil that prevents the valve from operating even when commanded. A failed indoor PCB can also produce this error if it is unable to drive the EEV or correctly interpret sensor data. Systematic checks should begin with address verification, then physical inspection of the EEV connector, followed by thermistor resistance testing and valve operation confirmation.

Source: manufacturer service documentation.

Common causes of E165

  1. 01

    Indoor unit address mismatch

    Wiring / connection

    If the indoor unit's address setting does not match the address the MCU is polling during the piping check, the unit will not respond and no temperature change will be recorded. Verify the DIP switch or software address setting on the indoor unit matches the MCU configuration.

  2. 02

    EEV disconnected or poorly seated at PCB

    Wiring / connection

    The electronic expansion valve (EEV) connector must be firmly seated at the indoor PCB for the valve to receive open and close commands. A loose, corroded, or unplugged harness will prevent refrigerant flow during the piping check, causing no temperature change at the EVAP OUT sensor.

  3. 03

    Faulty or failed EEV coil

    Part replacement

    Even when wiring is intact, a burned-out or mechanically stuck EEV coil will prevent the valve from opening. The coil can be tested for proper resistance and the valve can be checked for audible stepping during operation to confirm failure.

  4. 04

    EVAP OUT thermistor fault

    Part replacement

    A thermistor that has failed open, shorted, or become stuck at a fixed reading will not register any temperature change even if refrigerant is flowing normally. Testing the thermistor resistance against the expected temperature-resistance curve will confirm whether it needs replacement.

  5. 05

    Defective indoor PCB

    Part replacement

    If the indoor PCB cannot properly drive the EEV or read the EVAP OUT sensor signal, the piping check will fail regardless of the physical condition of those components. A defective PCB is typically diagnosed after all wiring, address settings, and components have been confirmed good.

See the test procedure for each cause

Frequently asked questions about E165

What does E165 mean on a Samsung air conditioner?
E165 means the system detected no change in the evaporator outlet temperature during its piping check routine. The piping check is designed to confirm that refrigerant is flowing properly through the indoor unit. When the sensor reading does not change as expected, the unit flags E165 and halts operation. The most common starting points for diagnosis are the indoor unit address configuration and the EEV connection to the PCB.
Can I fix E165 myself or do I need a technician?
Some steps, such as verifying the indoor unit address setting and visually inspecting the EEV wiring harness for a loose connection, can be performed by a knowledgeable DIYer comfortable working with electronics. However, testing EEV coil resistance, checking thermistor values, and replacing PCB components typically require proper tools and familiarity with refrigerant systems. If the wiring and address checks do not resolve the error, a certified technician should complete the diagnosis.
Is E165 on a Samsung air conditioner a safety concern?
E165 is a diagnostic fault rather than an immediate safety hazard. The system stops normal operation and reports the error to prevent running in an unverified state, which protects the compressor and refrigerant circuit from potential damage. You can leave the unit powered off until a technician evaluates it without risk of injury.
How much does it cost to repair E165 on a Samsung air conditioner?
Repair costs vary depending on the root cause. If only an address setting or a connector needs correction, costs are primarily for the service call and labor, typically in the range of $75 to $150. Replacing an EEV coil or thermistor adds parts costs, generally bringing the total to $150 to $400. A full PCB replacement is the most expensive scenario, often ranging from $300 to $600 or more depending on the model and labor rates in your area.
Will resetting the unit clear the E165 error?
A power reset may temporarily clear the error code and allow the unit to restart, but if the underlying cause is still present, the piping check will fail again and E165 will return. Resetting without fixing the root cause is not a lasting solution. Address the address configuration, EEV connection, thermistor, or PCB issue first to prevent the fault from recurring.

Related Samsung air conditioner codes

All Samsung air conditioner codes
View all 572 Samsung 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