3 troubleshooting – Reznor X Unit Installation Manual User Manual
Page 27

Form I-X, P/N 150491 R10, Page 27
10.3 Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY
Pilot will not
light (spark
ignition
system)
1. Manual valve not open.
1. Open manual valve.
2. Air in gas line.
2. Bleed gas line.
3. Dirt in pilot orifice.
3. Remove and clean with compressed air or solvent (do not ream).
4. Gas pressure too high or too low.
4. Adjust supply pressure. (See Paragraph 6.1.)
5. Kinked pilot tubing.
5. Replace tubing.
6. Pilot valve does not open.
6. If 24 volt available at valve, replace valve.
7. No spark:
7.
a) Loose wire connections
a) Be certain all wires connections are solid.
b) Transformer failure.
b) Be certain 24 volts is available.
c) Incorrect spark gap.
c) Maintain spark gap at 7/64".
d) Spark cable shorted to ground.
d) Replace worn or grounded spark cable.
e) Spark electrode shorted to ground.
e) Replace pilot if ceramic spark electrode is cracked or grounded.
f) Drafts affecting pilot.
f) Make sure all panels are in place and tightly secured to prevent drafts at pilot.
g) Ignition control not grounded.
g) Make certain ignition control is grounded to furnace chassis.
h) Faulty ignition controller.
h) If 24 volt is available to ignition controller and all other causes have been eliminated,
replace ignition control.
8. Optional lockout device interrupting control circuit by
above causes.
8. Reset lockout by interrupting control at thermostat.
9. Faulty combustion air proving switch.
9. Replace combustion air proving switch.
Pilot lights,
main valve
will not open
(spark Ignition
system)
1. Manual valve not open.
1. Open manual valve.
2. Main valve not operating.
2.
a) Defective valve.
a) If 24 volt is measured at valve connections and valve remains closed, replace valve.
b) Loose wire connections.
b) Check and tighten all wiring connections.
3. Ignition control does not power main valve.
3.
a) Loose wire connections.
a) Check and tighten all wiring connections.
b) Flame sensor grounded. (Pilot lights - spark continues) b) Be certain flame sensor lead is not grounded or insulation or ceramic is not cracked.
Replace as required.
c) Gas pressure incorrect.
c) Set supply pressure at 5" w.c. to 8" w.c. for natural gas and 11" w.c. for propane.
d) Cracked ceramic at sensor.
d) Replace sensor.
e) Faulty ignition controller.
e) See Paragraph 8.5. If all checks indicate no other cause, replace ignition controller. DO
NOT ATTEMPT TO REPAIR IGNITION CONTROLLER. THIS DEVICE HAS NO FIELD
REPLACEABLE PARTS.
Pilot will not
light (match-
lit system)
- NOTE: Units
manufactured
prior to 10/2003
1. Manual valve not open.
1. Open manual valve.
2. Air in gas line.
2. Bleed gas line.
3. Dirt in pilot orifice.
3. Remove and clean with compressed air or solvent (do not ream).
4. Gas pressure too high or too low.
4. Adjust supply pressure. (See Paragraph 6.1).
5. Bent or kinked pilot tubing.
5. Replace tubing.
6. Failed ECO device
6. Replace ECO device.
Pilot lights,
main valve
will not open
(Match-lit
system)
NOTE: Units
manufactured
prior to 10/2003
1. Manual valve not open.
1. Open manual valve.
2. Power not turned on or thermostat not calling for heat. 2. Turn on power; check fuses; turn on thermostat.
3. Circuit to valve open.
3. Check wiring and connections at transformer and thermostat.
4. Faulty transformer.
4. Replace the transformer.
5. Faulty or dirty thermocouple or safety pilot switch; or
failed ECO device
5. Clean and test with millivolt member or test. Replace defective part.
6. Faulty thermostat (see manufacturer's instructions)
6. Replace thermostat.
7. Faulty valve.
7. Replace valve or magnetic head.
8. High gas pressure.
8. Maximum supply gas pressure 8 oz. or 14" w.c.
9. Activated blocked vent switch.
9. Correct venting problem. Reset switch.
No heat
(Heater
operating)
1. Dirty filters in blower system.
1. Clean or replace filters.
2. Incorrect manifold pressure or orifices.
2. Check manifold pressure (See Paragraph 6.1.2).
3. Cycling on limit control.
3. Check air throughput (See Paragraph 6.3).
4. Improper thermostat location or adjustment.
4. See thermostat manufacturer's instructions.
5. Belt slipping on blower
5. Adjust belt tension
Cold air
delivered on
Startup; during
Operation
1. Fan control improperly wired
1. Connect as per wiring diagram.
2. Defective fan control.
2. Replace fan control.
3. Incorrect manifold pressure.
3. Check manifold line pressure (See Paragraph 6.1.2).
4. Blower set for too low temperature rise.
4. Slow down blower or increase static pressure.
air hose, an 18-24" long, 1/2" diameter furnace brush (or heavy wire with steel wool
securely attached), a flashlight, and a mirror are needed.
The furnace has "V" shaped baffles in the top of each heat exchanger tube. Follow the
instructions in
FIGURE 26 to remove the "V" baffles when cleaning the inner surfaces
of the heat exchanger.
NOTE: Furnaces manufactured prior to 3/95 may not have heat
exchanger "V" baffles.
Clean the inner surfaces of the heat exchanger from beneath using the brush to "scrub"
the tube walls to remove any accumulated dust, rust and/or soot. Clean the "V" tubes
and re-assemble the heat exchanger and the furnace.
Check the furnace for proper operation.