ARMY TM 9-4120-380-14
AIR FORCE TO 35E9-136-21
Request that Unit Maintenance set the thermostat (S2) to desired temperature If the unit has been regulated and
settings are satisfactory, It should not be changed.
Check that POWER ON light is on.
Set MODE SELECT switch to HEAT.
Check that HEAT light is on HEAT Light goes on and off with thermostat.
Check that CIRCULATE light is on.
Check that the following lights are off:
HIGH DISC PRESSURE,
LOW SUC PRESSURE, and
If any light (except POWER ON, HEAT, or CIRCULATE) Is on, turn MODE
SELECT switch to OFF. Contact unit maintenance.
Perform "during operation" preventive maintenance checks and services (table 2-1).