LG Heat Pump Error Code E336

E336 indicates a main cooling solenoid valve open error. This means the control board has detected an open circuit in the solenoid valve that manages refrigerant flow during cooling mode. The fault can originate from the valve coil itself, the wiring harness, or the connector between the valve and the board. The system will not operate normally until the fault is resolved.

The E336 error indicates the system cannot properly control refrigerant flow during cooling, which means continued operation could lead to reduced performance or additional component stress. It is best to stop using the heat pump in cooling mode and have the fault diagnosed promptly to avoid potential secondary damage.

Power cycling or resetting the unit may temporarily clear the error code from the display, but if the underlying fault, such as a failed solenoid coil or broken wire, is still present, the code will return once the system attempts to operate the valve again. A reset is not a repair, and the root cause must be addressed to permanently clear E336.

Some basic checks, such as inspecting and reseating wiring connectors, are within reach of a knowledgeable DIYer comfortable working around electrical components. However, diagnosing a failed solenoid coil requires a multimeter and familiarity with heat pump wiring. Any work involving refrigerant or control board replacement should be handled by a certified technician.

Repair costs depend on the root cause. Replacing a solenoid valve coil typically runs in the range of $150 to $400 including parts and labor. If the control board requires replacement, costs can rise to $400 to $900 or more depending on the model. A wiring repair is generally on the lower end of the cost range.