Thermo Products THV1M119A960SA, Installation And Operation Manual

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25
PSC AND CTM TROUBLE SHOOTING
DIAGNOSTIC FEATURES
The control board is equipped with 4 green Input Status LEDs and 1 red Board Status LED. These are
intended to provide a quick view into furnace performance without requiring a voltmeter.
The green Input Status LEDs are driven by the “Y”, “W”, “G”, and “DEHUM” inputs and are located
directly below those inputs. They will light to indicate the presence of these signals.
The red Board Status LED has two functions:
It will light when the board recognizes a valid input signal and will stay lit until all valid signals are
removed. This is intended to show that the board is functioning and able to respond to input signals.
It will flash rapidly while 120VAC is missing from the LIMIT switch. This is intended to give a quick
visual indication of the High Limit switch.