LG Heat Pump Error Code E433

E433 on an LG heat pump indicates that the system is restricting refrigerant charging operations because the outdoor ambient temperature is 15°C or above while the unit is in heating mode. This is a protective interlock built into the control system, not a component failure. It prevents inaccurate or potentially damaging refrigerant servicing under unsuitable ambient conditions. No immediate system damage is occurring when this code appears.

E433 itself is not a safety emergency and does not indicate that the heat pump is damaged or dangerous. It is a deliberate restriction to protect the system from being improperly serviced. Your heat pump's normal heating and cooling functions should not be affected by this code outside of a refrigerant charging procedure.

If E433 appeared during a routine refrigerant recharge visit, the cost to resolve it is simply the cost of rescheduling or returning when outdoor temperatures are appropriate, typically ranging from $100 to $300 or more depending on the service call and refrigerant needed. If the code is triggered by a faulty outdoor ambient temperature sensor, sensor replacement parts and labor can range from $75 to $250 depending on the technician and part availability.

E433 is primarily a servicing restriction that applies to refrigerant charging procedures, which legally require a certified technician to perform in most regions. If the code appeared during a professional service visit, the technician will need to reschedule for cooler outdoor conditions or switch to a compatible operating mode. Homeowners should not attempt to add refrigerant to the system themselves.

Resetting the unit may temporarily clear the displayed code, but the restriction will reactivate if a refrigerant charging sequence is attempted again while the outdoor temperature remains at or above 15°C in heating mode. Clearing the code without addressing the underlying condition of the servicing environment will not allow charging to proceed successfully.