TM 9-4120-407-14
Table 3-3. Unit Troubleshooting Table - Cont
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 1. Check that all doors, windows, and other openings in room or enclosure are tightly closed.
Tightly close all openings.
Step 2. Check that fresh air damper is not open.
Fully close fresh air damper by turning the control knob (1) to CLOSE. When condition
improves, adjust as necessary.
Step 3. Check adjustment of the potentiometer TEMPERATURE control (2).
Adjust the potentiometer TEMPERATURE control fully toward the WARM position. When
condition improves, adjust as necessary.
Step 4. Check that the evaporator air discharge (3) and return (4) grille louvers are fully open.
Fully open louvers.
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