TM 5-4520-253-13
(2) Turn fuel needle (2) counterclockwise in 1/8-turn increments. Increase fuel flow until there is no odor of
unburned fuel and no smoke in exhaust fumes.
(3) In low ambient temperatures it may be necessary to increase fuel flow to achieve smooth burner
operation.
d. If heater fails to start or operate properly, refer to table 3-3.
Section IV.
UNIT PREVENTIVE MAINTENANCE CHECKS AND SERVICES
3-16. GENERAL
a. Systematic, periodic Preventive Maintenance Checks and Services (PMCS) are essential to ensure that heater
is ready for operation at all times. In performing all PMCS, always keep in mind and observe WARNINGS and
CAUTIONS.
b. The purpose of a preventive maintenance program is to discover and correct defects and deficiencies before
they can cause serious damage or complete failure of equipment. Service intervals assigned provide reasonable
maintenance levels without excessive interruption of heater’s use.
3-17. PREVENTIVE MAINTENANCE CHECKS AND SERVICES
a. PMCS are provided in table 3-2.
b. All defects and deficiencies discovered during maintenance inspections must be recorded, together with cor-
rective action taken, on DA Form 2404, Equipment Inspection and Maintenance Worksheet.
c. Front and side doors provide access in area of carburetor and burner head. Access to combustion blower,
ventilating air motor, ignition transformer, and louver linkage is provided by removable side louver panels and bot-
tom cover.
d. Item numbers are assigned to each check or service task. These numbers are to be used as a source of item
numbers for the TM Number column on DA Form 2404, Equipment Inspection and Maintenance Worksheet, in record-
ing results of PMCS.
e. The service intervals are divided into two categories: M—Monthly, and Q—Quarterly. A dot (•) is placed in
the interval column for each check and service. lf the same check or service is made in two intervals, a dot is placed
in each applicable column.
f. The ITEM TO BE INSPECTED column lists the item to be checked or serviced.
g. The PROCEDURE column describes the procedure by which the check or service is to be performed, illustra-
tions are included to assist in locating that part of the equipment requiring the check or service.
h. An entry in the Equipment Is Not Ready/Available column will:
(1) Identify conditions that make the heater not ready/available for readiness reporting
purposes.
(2) Deny use of heater until corrective maintenance has been performed.
i.
For PMCS purposes, leaks shall be classified as follows:
(1) Class
(2) Class
Seepage of fluid (as indicated by wetness or discoloration) not great enough to
form drops.
I Leakage of fluid great enough to form drops but not enough to cause drops to
drip from item being checked/inspected.
(3) Class III Leakage of fluid great enough to form drops that fall from the item being
checked/inspected.
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