York TM9E furnace slow green flashing: Normal Standby
Info — not a fault
What does a slow green LED flash mean on a York TM9E furnace? The furnace control is operating normally with no thermostat calls. This is the standby state, not a fault code.
Safe checks before calling
If you expected heat, confirm the thermostat is set to HEAT with the setpoint above room temperature and any schedule allowing heat. This state means no call is reaching the control.
Questions about this code
What does a slow green LED flash mean on a York TM9E furnace?
The furnace control is operating normally with no thermostat calls. This is the standby state, not a fault code.
Does York TM9E furnace slow green flashing mean I need a repair?
No repair is needed for this state. If the thermostat is clearly calling for heat and the LED stays slow green, have a technician check why the heat call is not reaching the control.
How much does it cost to fix York TM9E furnace slow green flashing?
This normal standby state implies no repair bill. A service charge would apply only if a technician is needed to trace a missing heat call.
Applies to
TM9E
Different York generations use different code maps. If your series isn't listed, don't assume this meaning — check your blower-door label.
Verified against YORK TM9E Series Installation Manual — Single Stage ECM Residential Gas Furnaces, p.33
Verified against User’s Information Manual — All Residential Multi-position Gas Furnaces (33 in. models), p.5
Last verified 2026-10-07 · page updated 2026-10-07 · how we verify
Related York furnace codes
These codes use the same york tm9e single-stage ecm tri-color led control system.