York Heat Pump
Re: Replacement Demand Defrost Control Board - S1-33101975102
INSTALLATION
DEFROST CURVE SELECTION
When the control board is replaced the jumper MUST be placed in a numbered position. Select the proper jumper position.
If the jumper is missing or left in the P position, the replacement control will not energize the compressor.
► When the jumper position is changed, the control will not act upon the jumper changes until the thermostat calls are de-energized or power (24VAC) to the control is cycled.
The control will display the active defrost curve using the X/L terminal when the heat pump is operating in a defrost cycle that has been forced using the TEST input. For instance, the X/L output will be energized with two flashes when defrost curve 2 is active.
DEFROST COMPRESSOR DELAY
When Defrost Jumper Position #2 is selected the compressor is shut down for 30 seconds entering and exiting defrost mode.
The delay is present in a normal defrost but IS NOT present when the TEST pins are shorted to initiate a defrost cycle.