Reznor HRPD (Outdoor Duct Furnaces) Unit Installation Manual - Manual (Page 28)

Form I-RP/HRPD, P/N 132210 R14, Page 28
10.3 Troubleshooting
TROUBLE PROBABLE CAUSE REMEDY
Venter motor
will not start
(power-vented
system)
1. No power to the furnace. 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 or improper wire connections.
3. Venter relay defective. 3. Replace.
4. Defective motor or capacitor. 4. Replace defective part.
Pilot will not
light (Venter
operating on
power-vented
models)
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
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" 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 the ignition controller. This
device has no field replaceable parts.
f) Poor microamp signal f) Adjust pilot regulator
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).
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 1. Fan control improperly wired 1. Connect as per wiring diagram.
On Start-up 2. Defective fan control. 2. Replace fan control.
During
Operation
3. Incorrect manifold pressure. 3. Check manifold line pressure (See Paragraph 6.1).
4. Blower set for too low temperature
rise.
4. Slow down blower or increase static pressure.
10.0 Maintenance and Service (cont'd)