TM-9-2350-261-34

TM 9-2350-261-34

FINAL TEST - COOLANT HEATER — Continued

0070 00

Replace the blower if the heater goes out during test or smokes a lot and has heavy carbon deposits in the igniter cavity

(WP 0068 00). Moderate carbon deposits are normal and do not indicate a bad blower.

BURN TEST

Secure coolant heater to test stand (1) and coolant, fuel, electrical, and exhaust connections. Do not start the heater

unless there is an ample supply of coolant.

Remove heater end cover (2) and check inside for coolant leakage before starting burn test. Replace heater if coolant

has leaked.

Place heater control switch in START position and start timing heater immediately.

Note multimeter reading. Amperage draw must not exceed 12.8 amps (15.3 amps below 70F(21 C)).

Heater should ignite within 40 seconds from time heater control switch is turned on.

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

70F(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 0066 00).

If the heater fails to ignite or is slow to set flame, clean the igniter cavity and install a new igniter (see your -20).

If the flame detector switch does not transfer within the required time limits, the burner is bad. Replace heater if burner

is bad.

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 (WP 0062 00) and heater end cover.

0070 00-6

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