3 troubleshooting, 4 venter – Reznor EEDU Unit Installation Manual User Manual
Page 29

Form I-EEDU, P/N 150492 R6, Page 29
All Sizes -- After cleaning is complete, reverse the procedure to re-assemble the fur-
nace. Use extreme care so that no unsafe conditions are created.
Check the furnace
for proper operation.
10.3 Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY
Venter motor will
not start
1. No power to unit.
1. Turn on power, check supply fuses, or circuit breaker.
2. No 24 volt power to venter relay.
2. Turn up thermostat; check control transformer output. Check for loose wire
connections.
3. Venter relay defective.
3. Replace relay.
4. Defective motor or capacitor.
4. Replace motor or capacitor.
Pilot will not light
(venter operating)
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 .100".
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
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 14" w.c. for natural gas and 11" w.c. to 14"
w.c. for propane.
d) Cracked ceramic at sensor.
d) Replace sensor.
e) Faulty ignition controller.
e) If all checks indicate no other cause, replace ignition controller. Do not
attempt to repair ignition controller; it has no field replaceable components.
No heat (Heater
Operating)
1. Dirty Filters
1. Clean or replace filters.
2. Incorrect manifold pressure or orifices.
2. Check manifold pressure (See Paragraph 6.1).
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 1. Fan control improperly located or adjusted.
1. Relocate or adjust fan control (See Paragraph 8.3).
On Start-up
2. Defective fan control.
2. Replace fan control.
During
Operation
3. Blower set for too low temperature rise.
3. Slow down blower or increase static pressure.
4. Incorrect manifold pressure.
4. Check manifold line pressure (See Paragraph 6.1).
Motor will not run 1. Circuit open.
1. Check wiring and connections.
2. Fan control inoperative.
2. Replace fan control.
3. Defective motor or capacitor.
3. Replace motor or capacitor.
Motor turns
on and off
while burner is
operating (See
"Motor... " below)
1. Fan control improperly located or adjusted.
1. Relocate or adjust fan control (See Paragraph 8.3).
2. Defective fan control.
2. Replace fan control.
3. Motor overload device cycling on and off.
3. Check motor load against motor rating plate. Replace motor if needed.
4. 3 phase motor rotating in opposite direction. 4. Interchange 2 legs on supply connections.
Blower motor
cuts out on
overload
1. Improper motor pulley and/or adjustment.
1. See instructions on air throughput. (See Paragraph 6.3)
2. Improper static pressure in the duct system. 2. Adjust duct system dampers.
3. Low voltage.
3. Check power supply.
10.2.4 Venter
Motor - Remove dirt from the outer surface. The venter motor is permanently lubri-
cated; no oiling is required.
Venter Relay - The venter relay controls the venter motor. If relay contacts fail to
"make", the venter motor will not run. If relay contacts fail to "open, the venter motor
will not shut off.