LG Refrigerator Error Code Water Tank Heater Error

This error means the main control board has detected an open circuit in the water tank heater circuit, which prevents it from confirming the heater is functional. The heater keeps the internal water tank from freezing. The fault is usually caused by a disconnected wire, a bad connector at CN79 on the main PCB, a separated heater housing, or a failed heater element. The proper resistance across the heater circuit should measure 72 ohms, plus or minus 7 percent.

The error itself does not typically create an immediate safety hazard in most situations. However, a non-functional water tank heater can allow the internal water line or tank to freeze, which can block water dispensing or cause internal damage over time. It is best to address the fault promptly rather than leaving it unresolved, especially in refrigerators set to lower temperatures.

Repair costs vary depending on the root cause. If the fix only requires reseating a connector or securing a loose wire, there may be no parts cost at all, though a service call fee typically ranges from 75 to 150 dollars. If the water tank heater element needs replacement, parts and labor combined generally range from 150 to 350 dollars depending on the specific model and local labor rates. Diagnosing whether the issue is a wiring problem or a failed component first can help avoid unnecessary parts expense.

Start by disconnecting the CN79 connector from the main PCB and measuring resistance between the Pink and White wires using a multimeter. A reading of approximately 67 to 77 ohms indicates the heater element is intact, so the problem is likely a bad connection, corroded terminal, or broken wire in the harness. A reading of infinite resistance (open) means the heater element itself has failed and the component will need to be replaced. Always reseat the connector firmly before concluding the heater is bad.

A power reset may temporarily clear the error display, but the code will return if the underlying electrical fault in the water tank heater circuit is not corrected. The control board continuously monitors the heater circuit, so any open condition will trigger the error again. A reset is not a fix and should only be used after completing the proper resistance check and resolving the wiring or component issue.