York P2LBX16F14501, P3DHX12F08001 Check stack temperature. Stack temperatures will normally

Table C-3: System and General Troubleshooting continued

	Problem			Possible Cause						Remedy
				System	temperature			rise	too	System temperature rise ideally should not exceed 85°F. Check
										for clogged air filters. Check blower fan for excess dirt build-up
				high.
										or debris. Speed up blower fan if necessary.
										Check “fan off” delay timing setting. Use a duct thermometer in
				Poor “fan off” delay timing se-						the 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
				lection, (fan stops too soon).
										90° - 100°F. Manipulate the dip switch settings to come as close
Excessive fuel oil con-										as possible to this “fan off” temperature.
sumption.				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			ad-	Check thermostat heat anticipator setting against measured
										amperage draw. Increase heat anticipator setting if necessary.
				justed or in poor location.						If the thermostat is 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
				adjustment at oil burner, or						gain the highest practical CO2 or lowest practical O2 content in
Too much smoke.				improper draft pressure.						the flue gases. See Burner Set Up.
				Heat	exchanger			partially		Check for soot build-up in heat exchanger flue passages, espe-
				clogged.						cially in the outer radiator.
				Poor alignment			between		oil	Check alignment. air tube should be centered with fire pot
										burner opening. Oil burner head should be ¼ inch back from the
				burner blast tube and fire pot.
Soot building up on blast										inside surface of the fire pot.
tube (end coning).				Flame impingement caused by						Check nozzle size and angle. (See Appendix A). Check dis-
				Incorrect nozzle angle.						tance from head to inside surface of the fire pot.
				Defective fire-pot						Check fire-pot. Repair or replace.
				Airflow	blocked		or dirty air		fil-	Clean or replace air filter.
				ter.
				Thermostat		adjustments			or	Check thermostat heat anticipator setting against measured
										amperage draw. Increase heat anticipator setting if necessary.
				location.						If the thermostat is 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
Furnace	will	not	warm							rise is too high, speed up blower fan.
home to desired tem-										Test high limit function of all limit switches. Use a duct ther-
perature.				Defective high limit control.						mometer to assess accuracy of limit control. Check for obstruc-
										tions 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 ventila-
				intermittently on overload.						tion ports, clean if necessary. Replace motor if necessary.
				Burner motor stopping intermit-						Check burner motor. Replace if necessary.
				tently on overload.
Home	does	not	heat	Improper distribution of heat.						This is not likely to be a furnace problem. Balance duct system.
evenly
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