Lincoln 1451, 1450 service manual Not running, check for opens, shorts or grounds

		not running, check for opens, shorts or grounds.
		WITH POWER OFF: Turn motor to check for locked
		rotor. Replace burner blower motor as needed.
	Burner transformer	Check for 120VAC supplied to primary of burner
		transformer. If no voltage is present, trace wiring back
		to centrifugal switch of main fan motor. If voltage is
		present, check for 24VAC supply at transformer
		secondary. If there is primary voltage but no secondary
		voltage, replace burner transformer.
	Centrifugal switch of burner	Check for 24VAC at motor connector, wire #19 (input to
	blower motor	centrifugal switch) to neutral. If no voltage is present,
		trace wiring back to burner transformer. If voltage is
		present, check for 24VAC at wire #20 (output of
		centrifugal switch) to neutral. If no voltage is present at
		wire #20 and motor is running, replace burner blower
		motor.
	Ignition control	Check for 24VAC supply to the ignition control. If no
		voltage is present, trace wiring back to centrifugal
		switch of burner blower motor. If voltage is present,
		check for 24VAC at pin #3 and ground (pilot valve).
		NOTE: The Honeywell ignition control has a 30 second
		pre-purge (time delay) built in. If voltage is not present,
		replace ignition control. If the pilot valve is energized,
		check to see that the high voltage igniter circuit is also
		energized. To check, disconnect the igniter lead from
		the ignition control.
	No pilot flame	If the ignition control is supplied with 24Vac and the
		pilot valve (internal to valve assembly) and igniter
		circuits are energized, visually check for pilot flame.
		This may be done by opening the small inspection door
		on the end of the burner, or by opening the main oven
		door and looking under the lower finger housings on
		the right side of the oven. If no pilot flame is visible,
		check the pilot shut-off valve.
	Pilot shut-off valve	Check to see that the pilot shut-off valve is open (shut-
		off valve is located between valve assembly and
		burner).
	Pilot tube	Check for gas pressure at the pilot tube. Disconnect
		pilot tube at burner and connect a manometer to pilot
		tube. If no gas pressure is present during ignition,
		check for blockage in pilot tube or pilot shut-off valve. If
		these are clear, and there is gas supplied to the oven,
		replace the gas valve.
	Pilot orifice	If there is gas pressure at the pilot tube, check the pilot
		orifice for obstructions. Replace as needed.
	Burner igniter	Check the burner igniter head for any obstructions, also
		check for frayed or broken wire. Check spark gap (gap
		should be .100 to .125 inch). If there is visible damage,
		replace burner igniter.
	NOTE: Flame should be on
	at this time
Pilot flame, but no	Control transformer	Check for 120VAC supply to the primary of the control
main flame		transformer. If no voltage is present, trace wiring back
		to the oven power switch. If voltage is present, check
		foe 24VAC at the transformer secondary. If there is
		primary voltage, but no secondary voltage, replace
		control transformer.
	Oven control	Check for 24VAC supply to oven control. If no voltage
		is present, trace wiring back to control transformer. If
		24VAC is present, check for a read-out on the display.
		If there is 24VAC supplied, but there is no read-out on

Impinger I – 1450 Series Service Manual - Domestic 5