Thermo Products omd-70 service manual closed? If 120 VAC is

All installations and services must be performed by qualified service personnel.

After pre-purge, does the ignition control (GMD) or the oil primary (OMD) produce a spark at the ignition electrodes?

Yes

			On the GMD,has the burner
			motor centrifugal switch
			closed? If 120 VAC is
No	Is there 24 VAC across the power	No	measured across the switch,
			replace the burner motor. Else,
	terminals of the ignition control
			replace thermostat. On the OMD,
	module (GMD) or 120 VAC across
			try resetting the oil primary
	the ignition transformer (OMD)?
			control by depressing the
			RESET button. Check cad cell
			function. If all else fails,
	Yes		replace the oil primary.
	Check wiring to the electrodes and
	ignition control module fuse (GMD)
	or the ignition transformer and the
	electrodes (OMD). Also, check ignition
	electrode gap. Reset if necessary.
	Replace electrodes, ignition control
	module (GMD) or ignition transformer (OMD).

While ignition electrodes are sparking does fuel valve open?

Yes

No

Is there 24 VAC (GMD) across

"MV" terminals on ignition

control module during ignition attempt. Does the oil solenoid valve have 120 VAC across it during the ignition attempt (OMD)?

Yes

Check wiring to fuel valve.

If valve does not open,

replace fuel valve.

No

On the GMD, reset the module by interrupting power to system for more than one second. If this does not work, replace ignition control module. On the OMD, try resetting the oil primary control by depressing the RESET button. If this does not work, replace the oil primary.

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