FINAL TEST COOLANT HEATER Continued
A complete test of coolant heater consists of the following:
Fuel flow test (WP 0065 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 heater burns properly and
igniter cavity does not show undue carbon deposits.
Replace blower (WP 0072 00) if heater goes out during test or smokes a lot and has heavy carbon deposits in igniter
cavity. 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 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