Thomas & Betts UDAS, UDAP dimensions Troubleshooting cont’d, Cont’d

40. Troubleshooting (cont’d)

PROBLEM (cont’d)	PROBABLE CAUSE (cont’d)	REMEDY (cont’d)
Burner will not light	10. Integrated circuit board does not power	10.
(cont’d)	main valve.
	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 gas.
	d) Cracked ceramic at sensor.	d) Replace sensor.
Burner cycle on and off	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 gas.
	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	5.
	not closing.	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.
No heat (Heater	1. Incorrect valve outlet pressure or orifice.	1. Check valve outlet pressure. See Rating plate for manifold pressure.
Operating)	2. Cycling on limit control.	2. Check air throughput.
	3. Improper thermostat location or adjustment.	3. See thermostat manufacturer’s instructions.
Fan or venter motor will	1. Circuit open.	1. Check wiring and connections.
not run	2. Defective integrated circuit board.	2. Replace board.
	3. Defective motor or starter.	3. Replace motor or starter.
Fan or venter motor	1. Motor overload device cycling on and off.	1. Check motor load against motor rating plate. Replace motor if
turns on and off while		needed.
burner is operating
Fan or venter motor cuts	1. Low or high voltage supply.	1. Correct electric supply.
out on overload	2. Defective motor.	2. Replace motor.
	3. Poor air flow.	3. Clean motor, fan, fan guard, filter, and coils.
	4. Defective bearing or lubrication.	4. Lubricate bearings (motor permitting) or replace motor.

FOR SERVICE OR REPAIR, FOLLOW THESE STEPS IN ORDER:
FIRST:	Contact the Installer
	Name __________________________________________________________
	Address_________________________________________________________
	__________________________________________________________
	__________________________________________________________
	Phone _____________________________________
SECOND:	Contact the nearest distributor (See Yellow Pages). If no listing,
	contact Authorized Factory Representative, 1-800-695-1901 (Press 1).
THIRD:	Contact	REZNOR® / Thomas & Betts Corporation
		150 McKinley Avenue
		Mercer, PA 16137
		Phone: (724) 662-4400
		Date of

Model No. ______________Unit Serial No._____________________________ Installation _______________

(800) 695-1901; www.ReznorOnLine.com

	©2003 Thomas & Betts Corporation, All rights reserved.		Printed in the U.S.A.
	MANUFACTURER OF HEATING, COOLING, AND VENTILATING SYSTEMS
	Trademark Note: Reznor® , TCORE2® , and	are trademarks of Thomas & Betts.
Form RZ-NA I-UDA, P/N 195673 Rev 5, Page 36	1/03 YL Form RZ-NA I-UDA (Version .5)