Lennox O23 User manual

O23 Oil Furnace ◆ Up to 83% AFUE
Home Comfort Systems
LENNOX’ ELITE® SERIES
O23
Clean, quiet and comfortable home heating

The Elite® Series O23 oil furnace offers a clean, quiet and economical way to
keep your home warm and comfortable. High-quality components like the
Beckett burner reliably deliver heat to every room—year after year, with little
maintenance required.
CLEAN, QUIET AND COMFORTABLE HEATING,
WITH EASY MAINTENANCE
Built to exacting standards, the O23 furnace not only keeps you cozy and
comfortable—it also keeps your energy costs at a minimum. With efficiency
ratings of up to 83%, the O23 produces more heat per fuel dollar, which
means you’ll stay warm for less.
2
Efficient operation can result
in significant energy savings
Quality components ensure
long-lasting reliability
Simple, durable design
allows easy maintenance
and serviceability
Compact size fits easily in
almost any closet, crawlspace
or basement, leaving plenty
of room for add-on
air conditioning
Elite® Series O23 Oil Furnace
EFFICIENCY RATING
Up to 83% AFUE (Annual
Fuel Utilization Efficiency).
WARRANTY*
Limited lifetime warranty
on the heat exchanger.
5-year limited warranty
on all remaining covered
components.
Efficient Can save you
money each year on your
utility bills.
The O23 furnace is designed to
deliver lasting value and energy
savings. With heating efficiencies
of up to 83% AFUE, the O23 can
drastically reduce your energy costs,
compared to older furnaces.
This chart depicts potential energy savings you can
expect from the O23 furnace versus older furnaces with
lower efficiency ratings. Criteria used in this example
are 2,000 full-load heating hours, with a 80,000-Btuh
heating design load and $1.90 per gallon for oil. Your
actual savings will vary depending on the weather, local
fuel rates and your lifestyle.
Source: Energy Information Administration, U.S.
Department of Energy national average energy rates,
2005 forecast.
AFUE
83 %
vs. 55%
83 %
vs. 65%
$4000
$3500
$3000
$2500
$2000
0
$4033
3-YEAR HEATING SAVINGS
$2194
83% efficient O23 oil furnace vs.
55% and 65% equivalent AFUE units
*Applies to residential applications only.
See actual warranty certificate for details.
Innovation never felt so good.
™

3
THIS MODEL
81%-83%
INNOVATIVE FEATURES FOR ENHANCED COMFORT AND EFFICIENCY
Elite® Series O23 Specifications
O23 Up-flow Q2/3-70/90 Q3/4-105/120 Q5-140/154
AFUE 83% 81% 81%
Dimensions HxWxD (in.) 54 x 19-1/2 x 30-5/8 54 x 19-1/2 x 30-5/8 54 x 22-1/2 x 33-1/8
HxWxD (mm) 1372 x 495 x 778 1372 x 495 x 778 1372 x 572 x 841
OF23 Lo-Boy (Rear Flue) Q3/4-105/120R Q5-140/154R
OF23 Lo-Boy (Front Flue) Q3/4-105/120 Q5-140/154 OF23Q5-175/210R
AFUE 81% 81% 80%
Dimensions HxWxD (in.) 37 x 19-1/2 x 52-1/8 37 x 22-1/2 x 52-1/8 39 x 24 x 54-3/4
HxWxD (mm) 940 x 495 x 1324 940 x 572 x 1324 991 x 610 x 1391
OHR23 Down-flow/Horizontal Q3-105/120 Q5-140/154
AFUE 81% 81%
Dimensions HxWxD (in.) 59 x 20-1/2 x 20-1/2 59 x 23-1/2 x 23-1/2
HxWxD (mm) 1499 x 521 x 521 1499 x 597 x 597
Note: Due to Lennox’ ongoing commitment to quality, all specifications, ratings and dimensions are subject to change without notice.
Heavy-Gauge Steel Heat Exchanger –
Allows air to glide evenly over its smooth surface for
maximum heating efficiency.
Innovative Combustion Chamber –
Constructed from alumina-silica ceramic fiber, provides
quiet operation and high efficiency.
Beckett AFII Burner –
Delivers super-efficient combustion for greater
fuel economy.
Heavy-Duty Fuel Pump –
Provides quiet, reliable operation with fast shutoff of oil flow.
Insulated Blower Compartment –
Minimizes operating sounds.
Durable, Insulated Steel Cabinet –
Built to last and coated with a high-quality paint finish.
O23
Up to
83% AFUE

© Lennox Industries Inc. 2002
Visit us at www.lennox.com, or contact us at 1-800-9-LENNOX. PC41274(37M95) O23 1/06
 Air conditioner or heat pump
 Thermostat
 Furnace or air handler
 Filtration device
 Germicidal light
 Indoor coil
 Humidifier
 HEPA bypass filtration system
 Energy recovery ventilator
 Supply duct
 Return duct
CUSTOMIZE YOUR COMFORT
Lennox® heating, cooling and indoor air quality products are designed to provide efficient, economical comfort—
not only as individual units, but also together as an integrated system. This combined network of products delivers on
every comfort count, from consistent temperatures and balanced humidity to improved indoor air quality.
DEALERS YOU CAN COUNT ON
Choosing the right dealer for your home’s heating, cooling and air quality needs is every bit as important as choosing the
right brand. We think you’ll agree our independent dealers are a big reason you can count on quality customer service
whenever you call. Your Lennox dealer’s dedication to quality shows in his knowledge, training and expertise in designing
the right system for your home, installing it properly and keeping it running perfectly for many years to come.