TM 5-4520-241-14
2-6.
SHUTOFF.
a. To shut off the heater, turn the HEATER-OFF-FAN switch to OFF.
CAUTION
Do not disconnect the power cable from the power receptacle until the heater has
completed its purge cycle.
b. For several minutes after operation in the heater mode, the combustion and ventilating motors will continue to run.
This is perfectly normal since the burner will continue to burn until all fuel has been purged. After the fuel is burned and
the heater has cooled sufficiently, the heater will shut off.
SECTION II. OPERATION UNDER UNUSUAL CONDITIONS
OPERATION IN EXTREME COLD (BELOW 10 F) (-12.2 C).
2-7.
A thermostatically controlled fuel heater automatically heats the fuel when the temperature drops below 40 6 F
(1.1 to 7.8C). This preheating of the fuel aids combustion and ignition during extremely cold conditions. No operating
procedures are required for this fuel heater. You should take the following steps during extremely cold conditions:
a. Keep the fuel tank full to prevent condensation of moisture in the tank.
b. Clean snow and ice from fuel tank filler to prevent them from entering fuel tank, causing freezing in fuel lines.
c. Use the choke on the carburetor for starting (Diesel fuel or fuel oil only).
2-8.
OPERATION AT HIGH ALTITUDES.
a. The beater is designed to operate at elevations up to 10,000 feet above sea level without special service or
adjustment.
b. At 10,000-foot altitude, heat output may be reduced approximately 15 percent. This is a normal condition which
cannot be prevented, but optimum performance can be obtained by following all service instructions carefully.
2-9.
OPERATION UNDER RAINY OR HUMID CONDITIONS.
a. Wipe all accessible exposed areas frequently.
b. Paint all chipped or scratched surfaces to prevent rust.
c. Cover the heater when not in use.
2-7
