Reznor PDH Operation Manual PreevA - Manual (Page 35)

Form O-PreevA, P/N 234661R8, Page 35
Burner will not
light (cont’d)
d) Spark cable shorted to ground. d) Replace worn or grounded spark cable.
e) Spark electrode shorted to ground. e) Replace if ceramic spark electrode is cracked or grounded.
f) Burner not grounded. f) Make certain integrated circuit board is grounded to ignitor.
g) Circuit board not grounded. g) Make certain integrated circuit board is grounded to furnace chassis.
h) Unit not properly grounded. h) Make certain unit is properly field grounded to earth ground and properly
phased (L1 to hot lead L2 to neutral).
i) Integrated circuit board fuse blown. i) Correct cause. Replace fuse (type ATC or ATO, 32VDC, 3A).
j) Faulty integrated circuit board. j) If 24 volt is available to the integrated circuit board and all other causes have
been eliminated, replace board.
7. Lockout device interrupting control circuit
by above causes.
7. Reset lockout by interrupting control at the thermostat or main power.
8. SDH or SHH - Interlock door switch open 8. Close access door or replace switch.
9. Combustion air proving switch not
closing.
9.
a) Make sure unit is properly vented.
b) Remove obstructions from vent.
c) Replace faulty tubing to pressure switch.
10. Faulty combustion air proving switch. 10. Replace combustion air proving switch.
11. Main valve not operating. 11.
a) Defective valve. a) If 24v is measured at the valve connections and valve remains closed, replace
valve.
b) Loose wire connections. b) Check and tighten all wiring connections.
12. Integrated circuit board does not power
main valve.
12.
a) Loose wire connections. a) Check and tighten all wiring connections.
b) Flame sensor grounded. b) Be certain flame sensor lead is not grounded or insulation or ceramic is not
cracked. Replace as required.
c) Incorrect gas pressure. c) Supply pressure should be 5-14” w.c. for natural gas or 11-14” w.c. for propane.
Burner cycles
on and off - SDH/
PDH/RDH/SHH/
RHH
1. Gas pressure too high or too low. 1. Supply pressure should be 5-14” w.c. for natural gas or 11-14” w.c. for propane.
2. Burner not grounded 2. Make certain integrated circuit board is grounded to ignitor.
3. Circuit board not grounded. 3. Make certain integrated circuit board is grounded to furnace chassis.
4. Faulty integrated circuit board. 4. If 24 volt is available to the integrated circuit board and all other causes have
been eliminated, replace board.
5. Combustion air proving switch not
closing.
5.
a) Make sure unit is properly vented.
b) Remove obstructions from vent.
c) Replace faulty tubing to pressure switch.
6. Faulty combustion air proving switch. 6. Replace combustion air proving switch.
7. Flame sensor grounded. 7. Be certain flame sensor lead is not grounded or insulation or ceramic is not
cracked. Replace as required.
8. Cracked ceramic at sensor. 8. Replace sensor.
9. Incorrect polarity. 9. Reverse line volt leads to integrated circuit board.
10. Pin terminal loose at 9-pin plug. 10. Replace wire harness.
No heat - SDH/
PDH/RDH/SHH/
RHH
1. Incorrect valve outlet pressure or orifice. 1. Check valve outlet pressure. See rating plate for manifold pressure.
2. Cycling on limit control. 2. Check air throughput.
3. Improper thermostat location or
adjustment
3. See thermostat manufacturer’s instructions.
4. SHH - Vent temperature switch activated. 4. Identify reason (see Paragraph 3.4.6, page 16) and correct. Reset switch.
5. SHH - Heat exchanger condensate drain
pressure switch activated.
5. Clean condensate drain. Verify flow. Fill traps with water and restart heater.
Blower motor (all
Models) or venter
motor (SDH/PDH/
SHH/RHH/RDH)
will not run
1. Circuit open. 1. Check wiring and connections.
2. Defective integrated circuit board. 2. Replace board.
3. Defective capacitor, starter, or motor. 3. Replace defective part(s).
Blower motor (all
Models) or venter
motor (PDH/SDH/
RDH/SHH/RHH)
turns on and off
while burner is
operating
1. Motor overload device cycling on and off. 1. Check motor load against motor rating plate. Replace motor if needed.
Blower motor (all
Models) or venter
motor (SDH/
PDH/RDH/SHH/
RHH) cuts out on
overload
1. Low or high voltage supply. 1. Correct electric supply.
2. Defective motor. 2. Replace motor.
3. Poor air flow. 3. Clean motor, blower, blower guard, filter, and coils.
4. Defective bearing or lubrication. 4. Lubricate bearings (motor permitting) or replace motor
Blower motor (all
Models) cuts out
on overload
1. Improper motor pulley and/or
adjustment.
1. Check motor pulley and belt..
2. Improper static pressure in ductwork 2. Adjust duct system dampers.
3. Low voltage. 3. Check power supply.