Make:  York

Model or Series:  YHJF36 with AHX42

Type:  Heat Pump and Air Handler

Problem Description:  Unit making noise & head pressure a little high

Observed Symptoms:  

• Head pressure around 350 psi
• Head pressure drops when electric heat comes on
• Indoor blower speed increases when electric heat comes on

Solution:  Moved "Y" from the thermostat from Y1 to Y/Y2 at the air handler

Additional Information:  

• AHX air handler has 2 speeds - High and Low
• Low speed (Red wire) is for G and Y1
• High speed (White wire) is for Y/Y2 and Aux Heat
  • Y/Y2 should be used on all single stage applications