Samsung Air Conditioner Error Code E171

E171 indicates an indoor unit Electronic Expansion Valve open error, meaning the EEV in one of the indoor units is not closing when that unit stops operating. This allows refrigerant to leak into the stopped indoor unit, upsetting system pressure and triggering the fault. The error points to issues with the EEV coil seating, wiring connections to the PCB, the valve assembly itself, or the indoor PCB.

Continuing to operate the system with an active E171 error is not recommended. Refrigerant migrating into a stopped indoor unit disrupts system pressure balance, which can cause liquid refrigerant to reach the compressor and damage it over time. It is best to stop using the system and have it inspected promptly to avoid more costly secondary damage.

A power reset may temporarily clear the error display, but if the underlying cause such as a misseated EEV coil, wiring fault, or failed valve is still present, the E171 code will return once the system tries to close the EEV again. A reset alone does not fix the hardware condition that triggered the fault, so a proper diagnostic inspection is necessary to resolve it permanently.

Some steps are accessible to a knowledgeable DIYer, specifically checking that the EEV coil is properly seated on the valve body and that the wiring harness is securely connected to the indoor PCB. However, if those checks do not resolve the error, diagnosing a faulty EEV stepper motor or a defective PCB requires technical knowledge and potentially specialized tools. Any work involving the refrigerant circuit must be performed by a certified HVAC technician.

Repair costs depend on the root cause. If the fix is as simple as reseating the EEV coil or reconnecting a wiring harness, costs would primarily cover the service call, typically in the range of $75 to $150. Replacing an EEV assembly generally costs between $150 and $400 including parts and labor. A defective indoor PCB replacement can range from $250 to $600 or more depending on the model and labor rates in your area.