Error Code Reversed Polarity / Grounding Fault
York TM9V080B12MP11 Error Code Reversed Polarity / Grounding Fault: Reversed Polarity / Grounding Fault
TL;DR
Indicates reversed line voltage polarity, grounding problem or reversed low voltage transformer wires. Both heating and cooling operations will be affected. Check polarity at furnace and branch. Check furnace grounding. Check that flame probe is not shorted to chassis. The furnace will not start the ignition sequence until this problem is corrected. Disclaimer
This article is for informational purposes only and does not guarantee the accuracy or completeness of the information provided. Always turn off power and gas supply before attempting any repairs. If you smell gas, leave immediately and call your gas company. Consult a licensed HVAC technician for diagnosis and repair. Any actions taken based on this information are at your own risk. What Does Code Reversed Polarity / Grounding Fault Mean?
Indicates reversed line voltage polarity, grounding problem or reversed low voltage transformer wires. Both heating and cooling operations will be affected. Check polarity at furnace and branch. Check furnace grounding. Check that flame probe is not shorted to chassis. The furnace will not start the ignition sequence until this problem is corrected.
When to Call a Professional
Contact a licensed HVAC technician if:
- Basic troubleshooting did not resolve the error
- You smell gas at any point during the process
- You are not comfortable working around gas lines or electrical components
- The unit needs a gas valve, control board, or motor replacement