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Error code reference

Samsung Air Conditioner Error Code E235

Compressor sump temperature (oil temperature) sensor breakaway for digital compressor or fixed 1 compressor.

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Compressor sump temperature (oil temperature) sensor breakaway for digital compressor or fixed 1 compressor.

First step from the service manual

Check whether the relevant compressor sensor is broken away and reassemble.

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

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What E235 means on a Samsung air conditioner

Error code E235 on a Samsung air conditioner indicates a breakaway (open circuit or disconnected) condition detected at the compressor sump temperature sensor, also referred to as the oil temperature sensor. This sensor is mounted at the base of the compressor housing and monitors the temperature of the refrigerant oil in the compressor sump. The control board uses this data to protect the compressor from overheating and to verify that lubrication conditions are within safe operating parameters. The error applies specifically to the digital compressor or the fixed speed compressor designated as compressor 1 in multi-compressor systems.

A breakaway fault means the control board is reading an open circuit from the sensor circuit rather than a valid resistance value within the expected range. This typically points to a physically disconnected sensor connector, a broken sensor lead wire, or a failed sensor element that has lost continuity. Unlike a short-circuit fault, a breakaway condition confirms the signal has been completely lost rather than reading an out-of-range temperature value. In outdoor units exposed to vibration and thermal cycling, connector terminals can work loose over time, which is the most common cause of this fault.

The first recommended diagnostic step is to physically inspect the sump temperature sensor on the relevant compressor and confirm it is properly seated and connected. The sensor harness connector should be checked for corrosion, bent pins, or a loose latch. If the connector is secure, continuity testing of the sensor and its wiring harness will determine whether the sensor element itself has failed or the fault lies in the wiring between the sensor and the control board.

Source: manufacturer service documentation.

Common causes of E235

  1. 01

    Disconnected sensor connector

    Wiring / connection

    The most frequent cause is a sensor harness connector that has physically separated from the compressor sump sensor terminal. Vibration from compressor operation and repeated thermal expansion cycles can cause connectors to work loose over time. Inspecting and reseating the connector is always the first step.

  2. 02

    Broken sensor lead wire

    Part replacement

    The wiring between the sump sensor and the control board can develop an open break, especially near harness routing points where flex stress concentrates. A continuity test of the full wire run from the sensor to the board will confirm or rule this out.

  3. 03

    Failed compressor sump temperature sensor

    Part replacement

    The sensor element itself can fail internally, resulting in a permanent open circuit regardless of connector condition. If the connector is secure and wiring continuity is confirmed, the sensor should be tested for resistance and replaced if it reads open.

  4. 04

    Corroded or damaged connector terminals

    Part replacement

    Outdoor unit exposure to moisture can cause terminal corrosion inside the sensor connector, creating high resistance or an open connection even when the connector appears seated. Inspect terminals closely for green or white oxidation and clean or replace the connector as needed.

  5. 05

    Faulty control board

    Part replacement

    If the sensor and all wiring check out correctly but the error persists, the sensor input circuit on the main control board may have failed. This is the least likely cause and should only be considered after the sensor and harness have been ruled out.

See the test procedure for each cause

Frequently asked questions about E235

What does E235 mean on a Samsung air conditioner?
E235 indicates that the control board has detected a breakaway, or open circuit, condition at the compressor sump temperature sensor on the digital compressor or fixed compressor 1. This sensor monitors oil temperature at the base of the compressor to protect internal components. The system generates this fault when it loses the sensor signal entirely, which points to a disconnected connector, broken wire, or failed sensor.
Can I fix E235 on my Samsung air conditioner myself?
If the cause is simply a loose or disconnected sensor connector, a knowledgeable DIYer can locate the sump temperature sensor on the outdoor unit compressor, reseat the connector, and clear the error. However, if the sensor or wiring harness needs to be replaced, or if the outdoor unit must be partially disassembled to access the sensor, professional service is recommended. Working inside an outdoor refrigeration unit also requires caution around high-voltage components.
Is it safe to run my Samsung air conditioner with error code E235 active?
No, you should not continue running the unit with E235 active. The compressor sump temperature sensor is a protective component, and without a valid signal, the system cannot monitor oil temperature or prevent compressor overheating. Operating the unit in this condition risks serious compressor damage, which is a costly repair.
How much does it cost to repair a Samsung air conditioner showing E235?
If the fix is only a reseated connector, there may be no parts cost, and a service call fee is typically in the range of $75 to $150. If the sump temperature sensor itself needs replacement, parts and labor combined generally range from $150 to $400 depending on the unit model and local labor rates. A control board replacement, if required, can push costs significantly higher.
Will resetting my Samsung air conditioner clear the E235 error?
A power reset will temporarily clear the displayed error code, but E235 will return as soon as the control board re-checks the sensor circuit and detects the open condition again. The fault must be resolved at the hardware level by reconnecting or replacing the faulty sensor or wiring before the error will stay cleared permanently.

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