11. 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.
12. Remove heater end cover (2) and check
inside for coolant leakage before starting
burn test. Replace heater if coolant has
13. Place heater control switch in START
position and start timing heater
14. Note multimeter reading. Amperage draw
must not exceed 12.8 amps (15.3 amps
below 70°F (21°C) ).
15. Heater should ignite within 40 seconds from
time heater control switch is turned on.
16. 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 (page 1457).
17. If the heater fails to ignite or is slow to set
flame, clean the igniter cavity and install a
new igniter (see your 20).
18. If the flame detector switch does not
transfer within the required time limits, the
burner is bad. Replace heater if burner is
19. 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 (page 14-48) and heater end cover.
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