York D2CE, D2CG300 installation instructions TROUBLESHOOTING - Cont’d

530.18-N11Y

TROUBLESHOOTING - Cont’d.

4.The draft motor runs but the furnace does not light and the sparker does not spark.

a.The ignition control (IC1, IC2) may be locked out due to either a flame roll out or 100% shut off. These safety features are described above. If lock-out has occurred, 24V must be removed from the ignition controls. This is done at the unit or by resetting the room thermostat. After resetting 24V, check for proper furnace operation. If lock-out continues to occur, locate the source of the problem and correct.

b.Check all 24 volt connections from the relay board to and in the gas heat section. Check low voltage connec- tions to the (ETD) located in the control box.

c.If the furnace is hot, it may be out on an over-tempera- ture condition, wait for limit reset.

d.If the furnace is cold, check for 24 volts at wire 241 attached to the electronic time delay (ETD) located in the main control box. If 24 volts is not found, replace the ETD.

e.With the draft motor running, check for 24 volts at terminal 4 of (RW1-2) and (RW2-1). If 24 volts is not present, the centrifugal switch (CS) has not closed or has gone bad. Check the line voltage to the unit - if it is correct, replace the draft motor. If line voltage is low, call the power company.

f.Check for 24V at terminal 2 of (RW1-2 and RW2-1). If 24V is not present, check for 24V at (RW1 and RW2) relay coils. If these relays are pulled in, then check for a loose connection at terminal 2 and terminal 4 of each relay. If no problem is found, then replace (RW1 and/or RW2) as required.

g.If 24 volts is present at the ignitor controls, check all control wiring at the ignitor controls and the high tension wire to the ignitors. Check that the ground wires from the ignitor controls, the gas valves and pilot burners are all intact and making good electrical connection. Check to make sure that the ceramic insulator on the pilot ignitors or sensors is not broken or cracked, if all are intact, replace the ignition control IC1 or IC2.

5.The draft motor runs and the sparker sparks at the pilot burner but the pilot does not ignite and a gas odor is not detected at the draft motor outlet.

a.Check to make sure gas is being supplied to the unit. Make sure that the gas pressure to the unit is within the proper limits as described in the “POST START CHECK LIST” and that the pilot adjust screw is allowing some flow of gas as described in “PILOT CHECKOUT”.

b.Check all wiring between the ignitor control and the gas valve. Check to make sure the ground connections are intact.

c.If the wiring is intact, check for 24 volts across terminals “PV” and “COMMON” on the ignitor control. If 24 volts is not present, replace the ignitor control.

d.If 24 volts is present, remove the pilot burner and remove the pilot orifice from the pilot burner. The orifice is removed in the direction opposite the flow of gas. Inspect the orifice for obstruction. If it is clear, replace the main gas valve.

6.The sparker sparks at the pilot burner but the pilot does not ignite and a gas odor is detected at the draft motor outlet.

a.Adjust the pilot adjust screw on the gas valve as de- scribed in “PILOT CHECKOUT”.

b.Check the supply pressure as described in “POST START CHECK LIST”. Make adjustments as necessary.

c.Check the pilot orifice for obstruction as described in para. 5d. Clean as needed but the problem should not be the gas valve.

7.The pilot burner ignites but the sparker continues to spark and the main burners do not ignite.

a.Make the same checks and adjustment as described in para. 6.

b.Make sure that the pilot burner is not bent or damaged.

c.Make sure that the ground connections at the pilot burner, gas valve and ignitor control are intact. Check the high tension wire for good electrical connection. If all are intact, replace the ignitor module.

8.The pilot burner lights and the spark stops but the main burners do not light.

a.Check electrical connections between the ignitor con- trol and the gas valve. If intact, check for 24 volts across terminals “MV” and “COMMON” terminals. If no voltage detected, replace ignitor control. If voltage is present, replace gas valve.

9.Furnace lights with roll-out or one burner has delayed ignition.

a.Make sure that the pilot burner is aligned properly with the carryover as described in “PILOT CHECKOUT”.

b.Make sure that the carryovers on adjoining burners are screwed fast and are level with respect to one another.

10.Main burners light but exhibit erratic flame characteristics.

a.Adjust air shutters as described in “BURNER AIR SHUTTER ADJUSTMENT”.

b.Check the main burner orifices for obstruction and alignment. Removal procedure is described in “BURNER INSTRUCTIONS”. Clean or replace burner orifices and burners as needed.

22 Unitary Products Group