TM 5-4520-253-13
Table 3-3. Unit Maintenance Troubleshooting – Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 2.
Check air duct of combustion
blower.
If air duct has cracks, holes or
is badly dented, replace.
Step 3. Check combustion blower for loss
of power.
If blower runs slower then
usual at normal voltage,
forward heater to intermedi-
ate maintenance for repair
or replacement.
6. ROOM AIR CONTAMINATED WITH EXHAUST FUMES
Do not operate heater in enclosure unless ex-
haust gases are piped outside. Exhaust gases
contain carbon monoxide, a colorless, odor-
less, deadly poisonous gas. Failure to provide
proper elimination of the exhaust can cause
severe illness or death.
Step 1.
Check exhaust system.
a. Inspect for leaks caused by corrosion and loose connections.
Replace leaking exhaust line.
b. Check installation to determine whether exhaust fumes from outside are
being drawn back into room or enclosure.
Correct installation if needed. Test heated air as described in table 3-2,
item 15, to determine carbon monoxide level.
Step 2. Check heat exchanger.
If heat exchanger is leaking, forward heater to intermediate maintenance
for replacement.
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