2 Red Flashes — Limit Switch Fault

What does 2 Red Flashes mean?

The system has detected a limit switch fault. The gas valve and igniter will be off, but the indoor fan and inducer will remain on.

• High temperature limit switch is open
• Indoor (evaporator) fan motor is not operating correctly
• Faulty wiring to the limit switch
• Supply-air temperature rise is outside the expected range

Click steps to track your progress.

1. 1

   Check the operation of the indoor fan motor.

2. 2

   Verify the supply-air temperature rise matches the unit's nameplate.

3. 3

   Inspect the wiring and operation of the limit switch.

4. 4

   Reset the unit's power to clear the fault.