Goodman Air Conditioner Error Code F6

The F6 code on a Goodman air conditioner means the indoor discharge thermistor, identified by its yellow wire, is reading a temperature outside of the acceptable operating tolerances. The control board cannot validate the sensor's signal and flags the fault to protect the system. This code points directly to the thermistor as the first component to inspect and replace.

You should not continue running the system while the F6 fault is active. The control board uses the indoor discharge thermistor reading to make important decisions about safe operation, and running without a valid sensor signal can lead to undetected temperature conditions that may stress other components. Address the fault before resuming normal use.

A power reset may temporarily clear the F6 code, but if the yellow indoor discharge thermistor is faulty, the fault will return once the control board takes a new reading from the sensor. Resetting is not a fix and should only be used to confirm whether the fault is persistent or intermittent. The underlying sensor or wiring issue must be corrected for the code to stay cleared.

A knowledgeable DIYer can inspect the yellow thermistor wiring and connector for obvious damage such as loose connections, pinched wires, or corrosion. However, replacing the thermistor itself requires locating the correct replacement sensor and safely accessing the indoor unit. If you are not comfortable working inside the air handler or mini-split indoor head, a licensed HVAC technician should handle the repair.

If only the yellow indoor discharge thermistor needs replacement, parts and labor costs typically range from around $75 to $200 depending on your region and the specific unit model. If the wiring harness or control board is also involved, costs can increase to a range of $200 to $600 or more. Getting a diagnostic visit from a licensed technician will give you a more precise estimate for your situation.