Field Controls WML-C, MPL-B manual Timing

TABLE C-4: SYSTEM AND GENERAL TROUBLESHOOTING continued

Problem				Possible Cause						Remedy
			Electrodes out of adjustment or							Check electrode settings. Check electrodes for dirt build-up or cracks in
			defective.							porcelain.
			Poor	transformer		high		voltage		Check contacts between the igniter and electrodes. If OK, replace the
			connections		or		defective
										igniter
Oil burner	sputtering	at	transformer.
nozzle			Fuel oil filter clogged.							Replace fuel oil storage tank filter and / or fuel oil in-line filter.
			Defective oil pump.							Check burner motor / fuel oil pump coupling. Check oil pump pressure.
										Replace fuel oil pump if necessary.
			Fuel oil line		partially		clogged		or	Bleed air from oil line. If problem persists, replace oil line.
			contains air.
			System temperature rise too high.							System temperature rise ideally should not exceed 85°F. Check for
										clogged air filters. Check blower fan for excess dirt build-up or debris.
										Speed up blower fan if necessary.
										Check “fan off” delay timing setting. Use a duct thermometer in the
			Poor	“fan	off”	delay		timing		supply air plenum take-off or first few inches of the supply air trunk duct.
										Ideally, the fan will shut off at a temperature of 90° - 100°F. Manipulate
			selection, (fan stops too soon).
										the dip switch settings to come as close as possible to this “fan off”
Excessive	fuel	oil
										temperature.
consumption.
			Fuel oil leak.							Check fuel oil line for leaks. Repair or replace if necessary.
			Stack temperature too high.							Check stack temperature. Stack temperatures will normally range from
										350° to 450°F. Check draft regulator. Draft should be set to 0.02 in. w.c.
			Thermostat improperly adjusted or							Check thermostat heat anticipator setting against measured amperage
										draw. Increase heat anticipator setting if necessary. If the thermostat is
			in poor location.							being influenced by drafts, sunlight, duct work, etc., relocate to more
										suitable location.
			Insufficient		combustion				air	Adjust the oil burner combustion air band and draft regulator to gain the
			adjustment		at oil		burner,		or	highest practical CO2 or lowest practical O2 content in the flue gases.
Too much smoke.			improper draft pressure.							See Burner Set Up.
			Heat exchanger partially clogged.							Check for soot build-up in heat exchanger flue passages, especially in
										the outer radiator.
			Poor alignment between oil burner							Check alignment. Blast tube should be centered with fire pot burner
										opening. Oil burner head should be ¼ inch back from the inside surface
			blast tube and fire pot.
Soot building up on blast										of the fire pot.
tube (end coning).			Flame	impingement			caused		by	Check nozzle size and angle. (See Appendix A). Check distance from
			Incorrect nozzle angle.							head to inside surface of the fire pot.
			Defective fire-pot							Check fire-pot. Repair or replace.
			Airflow blocked or dirty air filter.							Clean or replace air filter.
										Check thermostat heat anticipator setting against measured amperage
			Thermostat		adjustments				or	draw. Increase heat anticipator setting if necessary. If the thermostat is
			location.							being influenced by drafts, sunlight, duct work, etc., relocate to more
										suitable location.
			Insufficient airflow.							Check all dampers. Open closed dampers including registers in unused
										rooms. Check system temperature rise. If temperature rise is too high,
Furnace will not warm home										speed up blower fan.
										Test high limit function of all limit switches. Use a duct thermometer to
to desired temperature.			Defective high limit control.
										assess accuracy of limit control. Check for obstructions to airflow around
										limit switch bi-metal elements. Replace control if necessary.
			Under-sized nozzle.							Check nozzle. If problem is not caused by air flow problems, use larger
										nozzle, if permitted by rating plate.
			Blower	fan	motor		stopping			Check blower fan motor amperage draw. Check motor ventilation ports,
			intermittently on overload.							clean if necessary. Replace motor if necessary.
			Burner		motor		stopping			Check burner motor. Replace if necessary.
			intermittently on overload.
Home does not heat evenly			Improper distribution of heat.							This is not likely to be a furnace problem. Balance duct system.

30 30318 R4 9/9/2005