York TM9T100C16MP11 Furnace Error Codes

Two Stage Gas Furnace | Control Board: Furnace Control Board

Not your model? View all York models →

Disclaimer
This information is for reference purposes only and does not guarantee accuracy or completeness. Always consult your owner's manual and a licensed HVAC technician for diagnosis and repair. Any actions taken based on this information are at your own risk.

All Error Codes

Code Name Severity DIY?
Slow Green Flash Normal Operation - No Thermostat Calls Info — →
Slow Amber Flash Normal Operation - Call for Heat Info — →
LED Steady Off No Power / Blown Fuse High ✗ Call a pro →
Steady On (Any Color) Control Failure High ✗ Call a pro →
Continuous Red Flash Twinning Error High ✗ Call a pro →
Continuous Amber Flash Low Flame Sense Current Low ✗ Call a pro →
1 Red Flash Flame Sensed Without Call for Heat High ✗ Call a pro →
2 Red Flashes Pressure Switch Stuck Closed High ✗ Call a pro →
3 Red Flashes Pressure Switch Open High ✗ Call a pro →
4 Red Flashes Main Limit Switch Open High ✓ Yes →
5 Red Flashes Limit Circuit Open Over 15 Minutes High ✗ Call a pro →
6 Red Flashes Pressure Switch Opened During Operation High ✗ Call a pro →
7 Red Flashes Ignition Failure - No Flame Detected High ✓ Yes →
8 Red Flashes Flame Lost Five Times (Recycle) High ✗ Call a pro →
9 Red Flashes Reversed Line Voltage Polarity / Grounding Problem High ✗ Call a pro →
10 Red Flashes Gas Valve Energized Without Call for Heat High ✗ Call a pro →
11 Red Flashes Limit Circuit Open 5-15 Minutes High ✗ Call a pro →
4 Amber Flashes Y Signal Without G Signal Low ✓ Yes →

How to Read the Error Code

The furnace has built-in, self-diagnostic capability. A blinking LED light on the control board can flash red, green or amber to indicate various conditions. The SLOW flash speed is two seconds on and two seconds off. The other flash codes turn on for 1/3 second and off for 1/3 second, repeated the number of times equal to the code, with a two-second pause between codes. The continuous flash codes flash the LED on and off continuously, with no breaks or longer pauses.

About This Model

The York TM9T100C16MP11 is a two stage gas furnace using the Furnace Control Board control board.