LG Air Conditioner Error Code CH72

CH72 means the LG air conditioner has detected a failure in 4-way valve transfer. The 4-way valve is the component that switches the system between heating and cooling modes by reversing refrigerant flow direction. The error triggers when the system commands a valve transfer but the pipe sensors do not confirm the expected result. The fault can originate from the pipe sensors, the valve coil wiring, or the valve coil itself.

It is not advisable to continue running the unit while CH72 is active. The system has shut down specifically because it cannot confirm proper refrigerant flow direction, which means it may not be heating or cooling correctly. Continuing to operate under these conditions could result in compressor stress or inadequate climate control. Address the fault before returning the unit to regular use.

A power reset may temporarily clear the CH72 code, but if the underlying fault is still present the error will return once the system attempts another mode transfer. A reset is useful for confirming whether a minor communication glitch caused the code, but it is not a repair. If CH72 reappears after a reset, a proper diagnostic inspection of the pipe sensors and 4-way valve coil is necessary.

Some causes of CH72 are accessible to a knowledgeable DIYer, such as reseating a disconnected pipe sensor connector or inspecting wiring for obvious damage. However, measuring coil resistance accurately, diagnosing refrigerant-side valve issues, and replacing components inside the refrigerant circuit require proper tools and in many regions a certified technician. If the basic connector checks do not resolve the error, professional service is recommended.

Repair costs vary depending on the root cause. A pipe sensor replacement is generally in the range of $50 to $150 including parts and labor. A 4-way valve coil replacement typically runs $100 to $250. If the full 4-way valve assembly requires replacement, costs can range from $200 to $600 or more depending on the model and labor rates in your area.