LG Air Conditioner Error Code CH45

CH45 on an LG air conditioner indicates a condenser pipe temperature sensor error. The fault is triggered when the sensor circuit is detected as open or shorted, or when the actual condenser pipe temperature rises too high. The system limits or stops operation to protect the compressor and refrigerant circuit from damage.

You should not continue running the unit with an active CH45 code. If the condenser is genuinely overheating, continued operation risks compressor damage and refrigerant system failures that are significantly more costly to repair. If the sensor has simply failed, operating without accurate temperature feedback removes an important protection layer from the system.

Repair costs depend on the root cause. Condenser coil cleaning is typically in the range of $75 to $200 as a service call. Replacing the condenser pipe thermistor generally falls between $100 and $250 including parts and labor. If a refrigerant recharge is needed, costs typically range from $150 to $400 depending on refrigerant type and the amount required. Control board replacement is the most expensive scenario, often ranging from $300 to $600 or more.

Some causes of CH45 are accessible to a knowledgeable DIYer, such as cleaning a blocked condenser coil or inspecting wiring connectors for visible damage or loose pins. However, testing the thermistor accurately requires a multimeter and knowledge of expected resistance values. Any diagnosis or repair involving refrigerant charge requires a certified HVAC technician by law.

A power reset may temporarily clear the CH45 code, but it will return quickly if the underlying fault is still present. If the sensor is failed open or shorted, or if the condenser pipe temperature remains too high, the control board will detect the fault again within a short operating period. A reset alone is not a repair and should only be used as part of diagnosing whether the fault is intermittent.