mypros+
Error code reference

Samsung Air Conditioner Error Code E157

Option setting error.

Samsung codesSamsung air conditioner codes

Option setting error.

First step from the service manual

Check SW03 option switch settings on indoor unit 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 E157.

  • 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 E157 means on a Samsung air conditioner

Error code E157 on a Samsung air conditioner indicates an option setting error related to the SW03 option switch on the indoor unit PCB (printed circuit board). This switch is a physical DIP switch or selector switch used to configure the unit's operational parameters, such as capacity settings, regional specifications, or feature configurations. When the control board reads a switch state that is invalid, unrecognized, or inconsistent with the expected configuration for that unit model, it throws E157 to alert the technician that the unit cannot operate correctly under its current settings.

The SW03 option switch must be set to a specific combination that matches the unit's installed configuration and regional requirements. If the switch positions are incorrect, for example after a PCB replacement where the new board was not configured to match the original settings, or if a switch contact has failed or become corroded, the board will detect a mismatch and trigger this error. Physical damage to the switch, solder joint failures on the PCB, or inadvertent changes to the switch during servicing are all potential causes.

Diagnosing E157 starts with a direct visual inspection of the SW03 switch on the indoor unit PCB. Technicians should verify that each switch position matches the required configuration for the specific model and installation. If a PCB has been recently replaced, cross-referencing the original board's switch settings before installation is critical. If the switch itself is damaged or contacts are not making reliable electrical connections, the PCB may require repair or replacement to resolve the fault.

Source: manufacturer service documentation.

Common causes of E157

  1. 01

    Incorrect SW03 switch configuration

    Wiring / connection

    The SW03 option switch on the indoor PCB is set to a combination that the control board does not recognize as valid. This is the most direct cause and is identified by comparing the current switch positions against the required configuration for the specific model.

  2. 02

    Switch settings altered during servicing

    Wiring / connection

    Accidental repositioning of SW03 during a previous repair or maintenance visit can change the configuration. Inspecting the switch positions and restoring the correct settings typically resolves the error without any part replacement.

  3. 03

    PCB replaced without replicating original switch settings

    Wiring / connection

    When a new indoor unit PCB is installed, the SW03 switch must be configured to match the original board's settings. If this step was skipped, the unit will immediately throw E157 on startup.

  4. 04

    Faulty or damaged SW03 switch

    Part replacement

    Physical damage, corrosion, or worn contacts on the SW03 switch can cause intermittent or incorrect signals to the control board even when switch positions appear correct. The switch or the PCB itself may need to be replaced.

  5. 05

    Defective indoor unit PCB

    Part replacement

    In some cases, the PCB itself may have a fault that causes it to misread the SW03 switch state, producing a false E157 error even when switch settings are correct. PCB replacement is required if all switch settings are confirmed accurate and the error persists.

See the test procedure for each cause

Frequently asked questions about E157

What does E157 mean on a Samsung air conditioner?
E157 indicates an option setting error on the indoor unit's control board. Specifically, the SW03 option switch on the indoor PCB is set to a configuration that the unit's control system does not recognize or accept. The unit will not operate normally until the switch is set to the correct positions for that model and installation.
How do I fix error E157 on my Samsung air conditioner?
Fixing E157 requires accessing the indoor unit PCB and inspecting the SW03 option switch. A technician will check the current switch positions and compare them against the correct configuration for the specific model. If the positions are wrong, adjusting them to the correct settings will clear the error. If the switch itself is damaged or the PCB is faulty, component replacement may be necessary.
Is error E157 on a Samsung air conditioner dangerous?
E157 is not a safety-critical fault involving refrigerant leaks, electrical shorts, or fire risk. It is a configuration error that prevents the unit from operating correctly. However, you should not attempt to bypass or ignore the error, as running a misconfigured unit could cause operational issues. Leave the unit off and contact a qualified technician to correct the switch settings.
Will resetting the Samsung air conditioner clear error E157?
A simple power reset will not permanently clear E157 because the root cause is a physical switch setting on the indoor PCB. Each time the unit powers on, it reads the SW03 switch and will re-trigger the error if the switch positions are still incorrect. The underlying configuration issue must be corrected before the error will stay cleared.
How much does it cost to repair error E157 on a Samsung air conditioner?
If the fix is simply adjusting the SW03 switch settings, the primary cost is the technician's labor for the service visit, which typically ranges from $75 to $200 depending on your location. If the SW03 switch or the indoor PCB needs to be replaced, parts costs can add $100 to $400 or more depending on the model and part availability. Getting a diagnosis from a certified technician is the best way to get an accurate estimate.

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