on a 13 seer York heat pump will the board stay in defrost after jumping the test pins like most other brands when the coil is iced?
When the TEST terminals are used to force a defrost cycle, the control will ignore the state of the liquid line temperature and outdoor ambient temperature inputs. The coil does not have to be cold and the outdoor temperature does not have to be within a certain range for the heat pump to be forced into a defrost cycle.
After the TEST terminal jumper is removed, the defrost mode will be terminated as normal - Liquid line temperature reaches 80F or after eight minutes of defrost operation.
The defrost cycle length timer will not be started until the TEST input is removed. If the TEST terminals remain shorted, the control will keep the unit in defrost mode.
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All LX except the 5 ton have time temp which work like any other time temp but the 5 ton LX and the affinity line have the York guard demand defrost board which is the sequence rundawg posted. The older steller series also use the York guard.