HVAC Code Lookup

Coleman Furnace LED Steady Off

WarningShown as: No LED activity at all

The control board LED is not flashing at all, which means the board is not getting power or its on-board fuse has blown.

Manual wording: “LED STEADY OFF - If the LED light does not flash at all, check for power to the board and check for a blown fuse on the board.”

Documented for: TG8S, TGLS, TG9S, TM8X, TMLX, TM9X, TM8T, TM9T, TM8V, TM9V

Likely causes, most common first

  1. No power reaching the control board
  2. Blown fuse on the control board
  3. Failed control board

What you can safely check yourself

  • Check the furnace breaker in the electrical panel is on
  • Check the furnace service switch near the furnace is on
  • Make sure the furnace door panel is fully seated - a loose door opens the door switch and kills power to the board

When to call a technician

If the breaker and switch are on and the door is seated but the LED stays dark, the fuse or the board needs a technician. A blown control-board fuse means something shorted, and that has to be found first.

A Coleman furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Sources

Other Coleman codes