LG Air Conditioner Error Code E153

E153 is a second-detection fault from the indoor unit's drain pump floating switch. It means the control board has confirmed that either the water level in the condensate drain pan has risen too high or the floating sensor that monitors water level is defective. The system triggers this code after detecting the fault condition on multiple checks, distinguishing it from a momentary or single-event fault.

Yes, this code should be addressed promptly. A genuine high-water condition in the drain pan means condensate is not draining properly and the unit may begin leaking water into your ceiling, walls, or floor. Running the system while the drain pan is overflowing can cause water damage to surrounding structures and potentially create mold growth over time.

A power reset may temporarily clear the E153 code, but because this is a second-detection fault, the underlying condition has already been confirmed by the system more than once. If the drain line is still blocked, the pump is still failed, or the sensor is still defective, the error will return quickly after reset. The root cause must be diagnosed and corrected before the code will clear and stay clear.

Start by disconnecting the floating sensor connector from the PCB and measuring resistance across the sensor terminals with a multimeter. If resistance reads infinity, replace the floating sensor. If the sensor tests normal, inspect the condensate drain line for clogs, verify the drain pump is running and moving water, and check the drain pan for standing water. Clearing a blocked drain line or replacing a failed pump will resolve the error if drainage is the actual problem.

Cost varies depending on the root cause. Clearing a clogged drain line yourself costs little to nothing, while professional drain cleaning service typically runs in the range of $75 to $200. Replacing a defective floating sensor generally costs between $20 and $80 for the part plus labor. A failed drain pump replacement, including parts and labor, typically falls in the range of $150 to $400 depending on the unit model and service rates in your area.