TM 9-2350-277-34
FINAL TEST – COOLANT HEATER — Continued
0077 00
4.
Note ammeter reading. Amperage draw must not exceed 12.8 amps (15.3 amps below 70
F (21
C)).
5.
Heater should ignite within 40 seconds from time heater control switch is turned on.
6.
The flame detector switch must transfer within 200 seconds. Transfer will be indicated by the pilot lamp and a drop in
amperage draw. Move the heater control switch to RUN. Amperage draw must not exceed 1.5 amps (4 amps below 70
F
(21
C)).
While burner is igniting and prior to flame switch transfer, check burner seal for signs of fuel leakage. If leakage is
present, replace packing gasket (WP 0082 00).
7.
If the heater fails to ignite or is slow to set flame, clean the igniter cavity and install a new igniter (see your -20).
8.
If the flame detector switch does not transfer within the required time limits, the burner is bad. Replace heater if burner
is bad.
9.
Allow the heater to burn one minute on HI heat, then move heater control HI-LO switch to LO. Burning and blower speed
should continue, but slow down. If the heater goes out, replace the fuel control valve and heater end cover (WP 0078 00).
10. Turn the heater control switch to OFF. Fuel flow and burning should stop in about 30 seconds. Blower should continue to
run from 1 to 3 minutes and then stop. If blower does not work within limits, readjust the flame detector switch (see your
-20). If the blower still fails to work within limits, replace the flame detector switch (see your -20).
TESTING RESTRICTION AND OVERHEAT THERMOSTATS
NOTE
Thermostat shown in fuel control valve is set to open at 70
F (21
C) and to close at 30
F (-1
C).
If temperature is below 70
F (21
C), the heating element in fuel control valve can be energized
during any operational cycle.
0077 00-6
