When the circuit board is energized, the indicator light should always illuminate, either in a flashing mode or in a continuous illumination mode, to indicate the microprocessor is processing information. The various illuminations of this light are described below:
No Illumination: The microprocessor is unable to process information. Check for proper system wiring.
Continuous Illumination: Will occur anytime a peak control signal is being received.
Slow Flash (4 second duration): Will occur during off-peak times. The illumination time of the light is in direct relation to the temperature information the transmitter is receiving from the outdoor temperature sensor. A long illumination time indicates warmer temperatures and a short illumination time indicates colder temperatures.