Error Code Twinning Error / Incorrect Phasing
York TM9T100C16MP11 Error Code Twinning Error / Incorrect Phasing: Twinning Error / Incorrect Phasing
TL;DR
Twinned furnaces must be on the same phase of power. Check voltage between the hot legs of power of each furnace — should read 0 volts. 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 Twinning Error / Incorrect Phasing Mean?
Twinned furnaces must be on the same phase of power. Check voltage between the hot legs of power of each furnace — should read 0 volts.
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