York Heat Pump: YZT Re: Communicating Defrost Board Fault Code Memory: The control stores the 10 most recent fault codes in memory. The codes are stored even when power is removed from the control and will remain in memory until they are manually cleared from the control. All codes...

York Heat Pump: YZT Re: Defrost Board - Push Button Functions The control has a PUSH BUTTON that can be used for various testing functions during installation and service. The Table below summarizes the behavior of the control when the PUSH BUTTON is pressed. Press Duration ...

York Heat Pump: YZT Re: Defrost Board Replacement When replacing a Communicating Defrost Board, it is required to manually set the unit tonnage before initial operation. Set the unit tonnage by adjusting the dip switches as shown in the table below. Switch 1 2 3 4 5 ...

York Heat Pump: YZT Re: High Pressure Lockout - Heating Mode The heat pump was running in normal heat mode (not in defrost) and the high pressure switch tripped. There are three levels of High Pressure fault: LED = On, 7-Segment = "0 1" ⇔ High Pressure Fault (No Lockout) LED = 2 Flashes,...