Goodman inverter system shows F8 and unit derates or shuts down in high ambient conditions
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety first: Turn off power at the outdoor disconnect before accessing sensors.
Steps to check:
- 1. Locate coil sensor: Find the thermistor clipped to the outdoor coil tubing on the Goodman condenser.
- 2. Inspect attachment: Ensure the sensor is firmly clipped to the coil and not dangling.
- 3. Check wiring and connector: Follow the sensor leads to the PCB and confirm the connector is secure and wires are intact.
- 4. Replace if damaged: Install a new Goodman-compatible outdoor coil thermistor if the original is cracked or corroded.
When to call a professional: If F8 persists, the outdoor control board may be defective and should be tested and replaced by an HVAC technician.
Repair Difficulty
Required Part
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