TM 5-4520-241-14
Table 4-2. Organizational Maintenance Troubleshooting - Continued
MALFUNCTION
TESTING OR INSPECTION
CORRECTIVE ACTION
7 - Continued
Step 2.
Inspect igniter. Open access doors and disconnect ignition cable from igniter. Remove igniter from
burner head and inspect for dirty or damaged electrode.
If igniter is damaged, discard it and install a new igniter in the burner head. If fuel deposits are
clogging tip between igniter electrode and ground tube, clean with a wire brush, then reinstall.
CAUTION
When checking spark, do not allow spark gap to exceed 1/8 inch. Greater gap will
cause excessively high potential buildup resulting in insulation breakdown either
internally or in the ignition cable. Always ground igniter body during inspection.
Step 3.
Check for ignition spark. Remove igniter from burner head, but make sure igniter is tightly
connected to ignition cable. Clamp igniter body against a heater case ground. Connect power
plug, check that room thermostat is set above ambient temperature, and turn on heater.
If spark is weak or intermittent, ignition transformer is defective. Turn off power and disconnect
power plug. Disconnect white and brown leads from transformer to terminal strip, and ignition
cable at transformer output. Remove screws and washers securing transformer to heater case,
and install new transformer by reversing removal process.
Step 4.
Check combustion air duct. Inspect for loose or damaged air duct.
Tighten clamps at burner head and combustion air motor outlet. If duct is punctured or t rn,
o
loosen clamps and remove damaged air duct. Install new duct and secure with clamps.
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