Lennox G71P User manual

7
1Air conditioner or heat pump
2Thermostat
3Furnace or air handler
4Filtration device
5Germicidal light
6Indoor coil
7Humidifier
8HEPA bypass filtration system
9Energy recovery ventilator
 Supply duct
 Return duct
 Dehumidifier system
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.
G71P Variable Capacity Gas Furnace ◆95% AFUE
Home Comfort Systems
G71P
The quietest furnace you can buy*—
and one of the most efficient!
Featuring new Precise Comfort™
and AirFlex™ Technologies

2
There’s no place like your home, especially when the air inside suits your
comfort level. The new G71P uses innovative Precise Comfort™technology
to create a living space with just the right amount of airflow and heat,
regardless of the temperature outside.
THE QUIETEST FURNACE YOU CAN BUY*—
AND ONE OF THE MOST EFFICIENT
Advanced technology that enhances your comfort also improves sound
performance and energy efficiency. The G71P is up to eight times quieter
than competitive models. And, with an energy rating of 95% AFUE, it can
save you up to $1000 each year on your utility bills.
Dave Lennox Signature®Collection G71P Gas Furnace
EFFICIENCY RATING
95% AFUE (Annual Fuel
Utilization Efficiency).
WARRANTY**
Limited lifetime warranty
on the heat exchanger.
10-year limited warranty
on all remaining covered
components.
Industry leading innovative
design ensures quiet
operation—up to eight
times quieter than its closest
competitor
Outstanding system efficiency
can save you hundreds of
dollars each year
Precise Comfort™technology
automatically adjusts heat and
airflow capacity in increments
as small as 1% for the ultimate
in temperature control
AirFlex™technology offers
custom settings which
can be selected to meet each
home’s specific year-round
comfort requirements
Zoning-compatible design
works with Lennox'
Harmony III™ zoning system,
seamlessly adjusting to deliver
the right amount of comfort
for up to four zones
ENERGY STAR®qualified
Innovation never felt so good.
™
PRECISE COMFORT™TECHNOLOGY
Thanks to new technological enhancements, the G71P constantly monitors
and automatically adjusts fan speed, heat and airflow capacity
demands to match the space requirements of your home—without
over-conditioning or wasting energy. It goes beyond typical low and high
two-stage operation, varying output from 40% to 100% in increments as small
as 1%. Because the G71P is so precise, your home stays perfectly comfortable
on milder days, the coldest days, and every day in between.
*Based on sound pressure levels during steady-state, high-fire operation of Lennox G71P-36B-070
and leading competitive units at mid-point temperature rise and minimum external static
pressure when set up per Section 4.5.3 of ARI 260.
Single-Stage
Furnace
(ON/OFF)
G71P Variable-
Capacity Furnace
(1% Increments)
Amount of heat
needed to maintain
an even temperature
(capacity requirements will
vary with outdoor conditions)
Heat Capacity in Btuh
Two-Stage
Furnace
(LOW/HIGH)
FURNACE TECHNOLOGY COMPARISON
Single-Stage
Furnace
(ON/OFF)
G71P Variable-
Capacity Furnace
(1% Increments)
Amount of heat
needed to maintain
an even temperature
(capacity requirements will
vary with outdoor conditions)
Heat Capacity in Btuh
Two-Stage
Furnace
(LOW/HIGH)
**Applies to residential applications only.
See actual warranty certificate for details.

MAXIMUM EFFICIENCY
The G71P delivers a highly-efficient
95% AFUE. Think of it this way: a
standard furnace operates like a car
in stop-and-go traffic–it's either
moving or sitting still, and burning
lots of fuel in the process. The G71P
operates more like highway driving
with the cruise control on, making
slight adjustments that allow
maximum fuel efficiency.
The G71P's variable speed motors
use up to two-thirds less electricity
than a standard single-speed motor,
too, which means it can significantly
reduce your energy costs. You may
also qualify for utility rebates.***
MINIMUM SOUND
The G71P furnace is much quieter
than other furnaces. Its variable
speed motor ramps up and
down slowly, so there’s no
sudden blast of air at startup.
And a specially insulated cabinet,
featuring patented noise-reducing
construction and SilentComfort™
technology, further reduces
operating sound to an
industry-leading low level.
***Check with your local utility about rebates in your area. 3
AIRFLEX™TECHNOLOGY
A blower setting for
every region
The G71P’s innovative AirFlex™
technology allows your Lennox
dealer to select the airside
performance best suited to your
lifestyle, home design and
geographic location.
Settings can be chosen to minimize
sound, reduce humidity, provide
increased airflow, or to combine
functions as needed. When paired
with a Lennox®air conditioner or
heat pump, the G71P is able to
provide customized comfort from
the outdoor cold of winter to the
extremes of summertime conditions.
This chart depicts potential energy savings you can
expect from the G71P furnace, versus older furnaces
with lower efficiency ratings. Criteria used in this
example are 2,000 full-load heating hours, with a
60,000 Btuh heating design load and $1.281 ccf for
gas. Your actual savings may vary, depending on the
weather patterns in your local area, local fuel rates
and your individual lifestyle.
Source: U.S. Environmental Protection Agency (EPA)
national average energy rates.
AFUE
95%
vs. 55%
95%
vs. 65%
$4000
$3500
$3000
$2500
$2000
$1500
$1000
$500
0
$3530
95% efficient G71P Gas Furnace vs.
55% and 65% AFUE units
$2240
3-YEAR HEATING SAVINGS
SOUND INTENSITY
The G71P is up to
8 times quieter than
its closest competitor1
1Based on sound pressure levels during steady-state, high-fire operation of Lennox G71P-36B-070 and leading competitive
units at mid-point temperature rise and minimum external static pressure when set up per Section 4.5.3 of ARI 260.
TEMPERATURE CONTROL COMPARISON
Single-stage furnace
G71P Variable-Capacity Furnace

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Dave Lennox Signature®Collection G71P Specifications
G71P G71P G71P G71P G71P
Model 36B-070 36C-090 60C-090 60C-110 60D-135
Heating Efficiency (AFUE) 95% 95% 95% 95% 95%
Dimensions HxWxD (in.) 40 x 17-1/2 x 28-1/2 40 x 21 x 28-1/2 40 x 21 x 28-1/2 40 x 21 x 28-1/2 40 x 24-1/2 x 28-1/2
HxWxD (mm) 1016 x 446 x 724 1016 x 533 x 724 1016 x 533 x 724 1016 x 533 x 724 1016 x 622 x 724
Note: Due to Lennox’ ongoing commitment to quality, all specifications, ratings and dimensions are subject to change without notice.
CUSTOMIZED COMFORT
The G71P variable-capacity furnace is designed to easily integrate with
other quality Lennox®products, assuring there’s a custom solution to match
your exact comfort level:
XC21 air conditioner is the most quiet and efficient central air conditioner
you can buy†
PureAir™air purification system cleans the air inside your home better
than any other single system you can buy
ComfortSense™touchscreen thermostat allows you to easily program ideal
temperature and humidity settings to match your family’s lifestyle
Harmony III™zoning system gives you room-by-room control of your
comfort and energy costs
For other ways to make your
home more efficient, visit
www.itpaystolivesmart.com.
IMPROVED AIR QUALITY
When you set your thermostat to “FAN,” the G71P continues to slowly
circulate air throughout your home at two-thirds less cost than a traditional
blower motor. That means you can run the fan constantly without significantly
increasing operating costs. It also means better indoor air quality—low-speed
fan operation increases the effectiveness of your filters, allowing them to
capture and remove more contaminants.
†A combination of sound ratings established per ARI's test standard: 270; and efficiency ratings established per ARI's test standard: ANSI/ARI 210/240-2005.
The G71P offers even greater system
efficiency when it's paired with an
electric heat pump. Called Dual
Fuel, this combination controls
heating costs by seamlessly
alternating between energy sources,
depending on outdoor conditions
and prevailing energy costs.
Many Lennox®home
comfort systems meet
ENERGY STAR®requirements
when used with appropriate
components. Ask your
dealer for details.
THIS MODEL
95%

Duralok Plus®Heat Exchanger –
Made of patented ArmorTuf™steel to
ensure high reliability and efficiency.
Special Sound-Absorbing Insulation –
Further reduces sound for quiet operation.
SureLight®Igniter – Silicone nitride
construction ensures long product life
and reliable operation.
Variable-Capacity Gas Valve –
Adjusts capacity output in 1%
increments for the ultimate in
precision comfort.
Robust Stainless Steel Secondary
Heat Exchanger – Time-tested design
allows the furnace to achieve high efficiency
levels by capturing additional heat.
Variable Speed Blower Motor –
Provides a quiet, consistent flow of air
for enhanced comfort, efficiency and
humidity control.
SureLight Control Board – Controls
all furnace operations to ensure high
reliability and efficiency. Direct
readout diagnostics for simple,
quick troubleshooting.
Durable Steel Cabinet – Made to
last with an attractive, high-quality
textured paint finish.
OUTSTANDING FEATURES FOR EXCEPTIONAL COMFORT AND EFFICIENCY
*Based on sound pressure levels during steady-state, high-fire operation of Lennox G71P-36B-070 and leading competitive units at mid-point temperature
rise and minimum external static pressure when set up per Section 4.5.3 of ARI 260.
G71P
95% AFUE
The quietest furnace
you can buy*—and one
of the most efficient!
Featuring new Precise
Comfort™technology
5
Quality you can trust.
Continuing our commitment to environmentally responsible design, the G71P
delivers the highest possible levels of energy efficiency and quiet operation, so
you can count on years of superior comfort and energy-saving performance.

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© Lennox Industries Inc. 2007
Visit us at www.lennox.com, or contact us at 1-800-9-LENNOX. PC50284(36W78) G71P 3/08
1Air conditioner or heat pump
2Thermostat
3Furnace or air handler
4Filtration device
5Germicidal light
6Indoor coil
7Humidifier
8HEPA bypass filtration system
9Energy recovery ventilator
 Supply duct
 Return duct
 Dehumidifier system
 Residential generator
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. Lennox
also offers a line of residential generators, which provide safe, reliable standby power in the event of outages.
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.