Lennox OF23Q3/4-105 User Manual

23 pages

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Page 1

504,627M

*P504627M*

01/04

*2P0104*

E 2002 Lennox Industries Inc.

Dallas, Texas, USA



Front

Flue Model

RETAIN THESE INSTRUCTIONS

FOR FUTURE REFERENCE

WARNING

Do not store or use gasoline or other flammable va-

pors and liquids in the vicinity of this or any other ap-

pliance.

WARNING

Improper installation, adjustment, alteration, ser-

vice, or maintenance can cause injury or property

damage. Refer to this manual. For assistance or

additional information, consult a qualified installer

or service agency.

CAUTION

When venting this appliance, keep vent terminal free

of snow, ice and debris.

INSTALLATION

INSTRUCTIONS

OF23 SERIES UNITS

OIL UNITS

504,627M

38152A060

01/04

Supersedes 04/02

Table of Contents

General 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Shipping & Packing List 1. . . . . . . . . . . . . . . . . . . . . . .

OF23 Unit Dimensions 2. . . . . . . . . . . . . . . . . . . . . . . . . .

OF23 Start−Up & Performance Check List 2. . . . . . .

OF23 Unit Parts Arrangement 3. . . . . . . . . . . . . . . . . . . .

OF23 Oil AFII Burner Parts Arrangement 4. . . . . . . . . .

Requirements 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Locate & Level Unit 4. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Unit Adjustments 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Venting 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Flue Connect ions 11. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Supply & Return Air Plenums 11. . . . . . . . . . . . . . . . . . . .

Oil Supply Lines Sizing 11. . . . . . . . . . . . . . . . . . . . . .

Connect Oil Supply Line and Filter 13. . . . . . . . . . . . .

Leak Check 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Electrical Wiring 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Start−Up & Adjustment 15. . . . . . . . . . . . . . . . . . . . . . . . .

Service 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Troubleshooting 17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

General

These instructions are intended as a general guide and do

not supersede local codes in any way. Only qualified tech-

nicians can install and service the Lennox Elite

Series

OF23 oil furnaces. In Canada, refer to CSA B139 for rec-

ommended installation procedures. Consult authorities

who have jurisdiction before installation.

CAUTION

Never burn garbage or paper in the heating system.

Never leave papers near or around the unit.

Shipping & Packing List

1− Assembled oil furnace

1− Barometric draft control

1− Side exhaust pipe collar (front flue units only)

1− Direct intake collar (AFII burner units only)

Check the components for shipping damage. If you find any

damage, immediately contact the last carrier.

Litho U.S.A.

Questions and Answers:

C
Carrie WoodAug 16, 2025
What to do if Lennox OF23Q3/4-105 burner starts and locks out?
- A
  april49Aug 16, 2025
  If your Lennox Furnace burner starts and fires but then locks out on safety, it could be due to several reasons related to air and combustion. Check for an unbalanced fire and replace the nozzle if necessary. If there's too much air, reduce the combustion air and check combustion. Conversely, if there's too little air, increase the combustion air and check combustion. Excessive draft can be corrected by adjusting the barometric damper. Insufficient draft or a restriction should be corrected or removed. A dirty cad cell face should be cleaned, and a faulty cad cell should be replaced. Lastly, a defective primary control circuit may require replacement of the primary control.
J
jason05Aug 25, 2025
What to do if Lennox OF23Q3/4-105 runs continuously?
- D
  David MartinAug 25, 2025
  If your Lennox Furnace burner runs continuously and produces too much heat, several thermostat-related issues may be the cause. Check for shorted or welded thermostat contacts and repair or replace the thermostat if needed. If the thermostat bimetal is stuck, clear any obstruction or replace the thermostat. Ensure the thermostat is level. Repair any shorted thermostat wires or replace them. If the thermostat is out of calibration, replace it. Correct any cold drafts affecting the thermostat or relocate it. Finally, a defective primary control may also cause this issue, requiring replacement.