TM 9-4120-403-14
2-10. OPERATION IN HI HEAT MODE
In the HIGH HEAT mode, six heaters are activated. Three are thermostatically controlled. Three operate
all of the time.
a. Turn mode selector switch to HI HEAT.
b. Switch fan speed switch to HIGH SPEED.
c. Turn TEMPerature control thermostat knob as far as if will go in the INCREASE (warmer) position.
Figure 2-11. HI HEAT Control Setting
d. When room or enclosure temperature reaches the desired level, slowly turn the TEMPerature control
thermostat knob toward DECREASE. Make small adjustments until desired temperature is maintained
automatically.
NOTE
Should unit continue to produce too much heat with TEMPerature control thermostat knob adjusted toward
the decrease setting, switch to LO HEAT and LO SPEED.
e. Adjust fresh air damper (door) to desired setting. It is normally better to keep the fresh air damper
slightly open. Damper should be closed during very cold weather and during fast warmup periods.
Figure 2-12. Fresh Air Damper (Door) Adjustment
2-19
