Samsung Air Conditioner Error Code E318

E318 indicates a low pressure sensor breakaway fault, meaning the control board has lost the signal from the low-side refrigerant pressure sensor. The unit stops normal operation to protect the compressor from running under unknown pressure conditions. The cause is typically a disconnected connector, a damaged wire, or a failed sensor.

No, you should not attempt to run the unit while E318 is active. The low pressure sensor provides critical data that protects the compressor from operating under conditions that could cause serious damage. Continued operation without a functioning pressure sensor risks compressor failure, which is a costly repair.

Repair costs depend on the root cause. If only a connector needs reseating or cleaning, the cost may be limited to a service call fee, typically in the range of $75 to $150. Replacing the low pressure sensor itself generally adds $50 to $200 in parts. If the main control board is at fault, total repair costs can range from $300 to $600 or more depending on the unit model and labor rates in your area.

Some causes of E318, such as a loose wiring connector, can be addressed by a knowledgeable homeowner after safely powering down the unit. However, if the fault involves refrigerant handling, sensor replacement inside sealed components, or control board diagnosis, a certified HVAC technician should perform the work. Working inside air conditioning equipment carries electrical and refrigerant safety risks.

A power reset may temporarily clear the error code, but if the underlying fault with the low pressure sensor or its wiring is still present, the code will return once the system attempts to restart. A reset is useful for confirming whether the fault is intermittent, but it is not a substitute for diagnosing and repairing the root cause.