Service manual

12B.5 No Reversing Valve Operation Electric Heat Mode

Note: All Operating Functions Subject To Thermostat And P.C. Board Time Delays.

Thermostat and/or Sub-base Must Be In The Electric Mode.

Note: If the Compressors or Fan Motors are not Running, Refer To Proper Checkouts.

Important Notice:

If the unit is equipped with a high pressure switch and this switch opens, it

Opens the 12 VDC (-) negative circuit from the thermostat to the P.C. Board

and all heat pump functions are dead. Be sure to correct the root problem causing

the high head pressure. If any heat pump function operates, the switch is OK.

Note:

Reversing Valve Solenoid Is Energized In The Electric Heat Mode

Once The Reversing Valve Solenoid Has Energized, The P.C. Board Locks

The Valve Into An Energized Position Until The Wall Thermostat Is

Placed In The Cool Position And Actually Has A Demand For Cooling,