mypros+
Error code reference

Samsung Air Conditioner Error Code E374

Heat sink temperature sensor error of inverter PBA2.

Samsung codesSamsung air conditioner codes

Heat sink temperature sensor error of inverter PBA2.

MyPros+ Max

Get the full diagnostic procedure for E374.

  • 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 E374 means on a Samsung air conditioner

Error code E374 on a Samsung air conditioner indicates a heat sink temperature sensor fault on the inverter PBA2 (Printed Board Assembly 2). The heat sink temperature sensor monitors the thermal state of the inverter power board's heat sink, which dissipates heat generated by the power transistors and switching components during compressor operation. When the control system detects a signal from this sensor that falls outside the expected range, whether an open circuit, short circuit, or out-of-range resistance reading, it triggers E374 and halts inverter operation to prevent thermal damage.

The inverter PBA2 is responsible for converting DC power to variable-frequency AC power to drive the compressor at varying speeds. The heat sink attached to this board can reach significant temperatures during operation, and accurate sensor feedback is critical for thermal protection. A faulty sensor can report falsely high or falsely low temperatures, either causing unnecessary shutdowns or, more dangerously, failing to trigger a shutdown when the board is genuinely overheating.

Common causes of this error include a damaged or disconnected sensor, wiring harness faults between the sensor and the PBA2, corrosion at connector terminals, or an actual overheating condition that has degraded the sensor itself. In some cases, the inverter PBA2 may have internal damage affecting the sensor input circuit, requiring board-level diagnosis or replacement.

Source: manufacturer service documentation.

Common causes of E374

  1. 01

    Faulty or failed heat sink temperature sensor

    Part replacement

    The sensor itself may have failed, producing an open circuit or short circuit reading outside the expected resistance range. This is the most frequent root cause and can be confirmed by measuring the sensor's resistance with a multimeter.

  2. 02

    Loose or disconnected wiring connector

    Wiring / connection

    The connector linking the heat sink temperature sensor to the inverter PBA2 may have come loose due to vibration or poor seating. Inspect the connector and wiring harness for disconnection, damage, or corrosion at the terminals.

  3. 03

    Corroded or damaged wiring harness

    Part replacement

    Moisture intrusion or long-term heat exposure can corrode connector pins or degrade wire insulation along the sensor harness, causing intermittent or permanent signal loss. Visual inspection and continuity testing of the harness wires can identify this condition.

  4. 04

    Actual overheating of the inverter heat sink

    Wiring / connection

    If airflow through the inverter section is restricted by debris, a blocked filter, or a failed cooling fan, the heat sink can overheat and degrade or destroy the sensor. Check for airflow blockages and verify that all cooling fans are operating correctly.

  5. 05

    Defective inverter PBA2

    Part replacement

    If the sensor and wiring both test within specification, the fault may lie in the sensor input circuit on the inverter PBA2 itself. Board-level failure requires replacement of the inverter PBA2.

See the test procedure for each cause

Frequently asked questions about E374

What does E374 mean on a Samsung air conditioner?
E374 indicates a heat sink temperature sensor error on the inverter PBA2, which is one of the main power control boards in the unit. The system has detected that the sensor monitoring the board's heat sink is producing an abnormal signal, either due to a sensor failure, wiring fault, or an actual overheating condition. The unit shuts down to prevent damage to the inverter components. A technician will need to inspect the sensor, wiring, and board to isolate the fault.
Can I fix E374 on my Samsung air conditioner myself?
Basic checks such as inspecting the wiring harness and connector for visible damage or looseness can be done by a knowledgeable DIYer. However, diagnosing and replacing the heat sink temperature sensor or the inverter PBA2 requires working near high-voltage components inside the unit and should be performed by a qualified technician. Improper handling of inverter board components carries a serious risk of electric shock.
Is it safe to keep running my Samsung air conditioner when E374 is showing?
No. The E374 error typically causes the unit to shut itself down precisely because continued operation without reliable heat sink temperature monitoring risks overheating and permanent damage to the inverter power board. Do not attempt to force the unit to run while this error is active. Have the fault diagnosed and repaired before resuming normal operation.
Will resetting my Samsung air conditioner clear the E374 error?
A power reset may temporarily clear the error code and allow the unit to restart, but if the underlying fault in the sensor, wiring, or board remains, the error will return quickly. A reset is not a repair. It can be useful to confirm whether the fault is intermittent, but a proper diagnosis of the sensor and inverter PBA2 is still required.
How much does it cost to repair an E374 error on a Samsung air conditioner?
Repair costs vary depending on what component has failed. If only a sensor or wiring repair is needed, costs are generally in the range of $100 to $250 including labor. If the inverter PBA2 requires replacement, the total cost including parts and labor can range from $300 to $700 or more depending on the model and part availability. Getting a diagnostic assessment from a certified technician before committing to a repair is advisable.

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