FINAL TEST COOLANT HEATER Continued
Conduct the heater exhaust away from the test area. Use an exhaust extension made of flexible hose (8) not more than 10
A complete test of the coolant heater consists of the following:
Fuel flow test (WP 0078 00).
Restriction thermostat test.
Overheat thermostat test.
Combustion air blower test.
Obtaining equipment for the combustion air blower test may be difficult. Do not do this test if the heater burns properly
and the igniter cavity does not show undue carbon deposits.
Replace the blower if the heater goes out during test or smokes a lot and has heavy carbon deposits in the igniter cavity
(WP 0084 00). Moderate carbon deposits are normal and do not indicate a bad blower.
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
Place heater control switch in START position and start timing heater immediately.