EnglishDeutsch
 logo
Brands
  1. Home
  2. •
  3. Brands
  4. •
  5. Lennox
  6. •
  7. Furnace
  8. •
  9. Lennox G40 User manual

Lennox G40 User manual

Other Lennox Furnace manuals

Lennox Allied Air Enterprises A95DF2V User manual

Lennox

Lennox Allied Air Enterprises A95DF2V User manual

Lennox E12Q2-05 Operating and installation instructions

Lennox

Lennox E12Q2-05 Operating and installation instructions

Lennox SLP98UHV SERIES User manual

Lennox

Lennox SLP98UHV SERIES User manual

Lennox Elite G61MPV36B-045 User manual

Lennox

Lennox Elite G61MPV36B-045 User manual

Lennox SL297UHNV Series Installation and operation manual

Lennox

Lennox SL297UHNV Series Installation and operation manual

Lennox 80MGF User manual

Lennox

Lennox 80MGF User manual

Lennox EL296DFV SERIES Guide

Lennox

Lennox EL296DFV SERIES Guide

Lennox SL280UHV Operator's manual

Lennox

Lennox SL280UHV Operator's manual

Lennox G40UH Series User manual

Lennox

Lennox G40UH Series User manual

Lennox SL280UHV Guide

Lennox

Lennox SL280UHV Guide

Lennox EL195UHE Elite Series User manual

Lennox

Lennox EL195UHE Elite Series User manual

Lennox ML180UHE User manual

Lennox

Lennox ML180UHE User manual

Lennox ML193DF Guide

Lennox

Lennox ML193DF Guide

Lennox 80UGH Installation and operation manual

Lennox

Lennox 80UGH Installation and operation manual

Lennox Signature G60UHV36A-070 User manual

Lennox

Lennox Signature G60UHV36A-070 User manual

Lennox O23 User manual

Lennox

Lennox O23 User manual

Lennox G21 V SERIES User manual

Lennox

Lennox G21 V SERIES User manual

Lennox Allied Air A80DF User manual

Lennox

Lennox Allied Air A80DF User manual

Lennox G40UHX Series Guide

Lennox

Lennox G40UHX Series Guide

Lennox 80G1DF User manual

Lennox

Lennox 80G1DF User manual

Lennox Allied Air A96DF2E User manual

Lennox

Lennox Allied Air A96DF2E User manual

Lennox G50DF(X)?24A?045 User manual

Lennox

Lennox G50DF(X)?24A?045 User manual

Lennox EL296UHV series User manual

Lennox

Lennox EL296UHV series User manual

Lennox EL195DF SERIES User manual

Lennox

Lennox EL195DF SERIES User manual

Popular Furnace manuals by other brands

Armstrong EG7H SERIES Installation and maintenance instructions

Armstrong

Armstrong EG7H SERIES Installation and maintenance instructions

Payne PG92ESA Installation, start-up, operating and service and maintenance instructions

Payne

Payne PG92ESA Installation, start-up, operating and service and maintenance instructions

SUPREME FEM10-M2301CM-A Installation instructions and homeowner's manual

SUPREME

SUPREME FEM10-M2301CM-A Installation instructions and homeowner's manual

Ingersoll-Rand S9V2B080D4VSAC/D Installer's guide

Ingersoll-Rand

Ingersoll-Rand S9V2B080D4VSAC/D Installer's guide

Johnson Controls TM9T User's information manual

Johnson Controls

Johnson Controls TM9T User's information manual

Fluke 9118A user manual

Fluke

Fluke 9118A user manual

Intertherm M7RL Series user manual

Intertherm

Intertherm M7RL Series user manual

HDG Pelletmaster 15 Operation manual

HDG

HDG Pelletmaster 15 Operation manual

Pinnacle Aero Bella AB-716C-QH User's manual and operating instructions

Pinnacle

Pinnacle Aero Bella AB-716C-QH User's manual and operating instructions

Nortek MG2S Series installation instructions

Nortek

Nortek MG2S Series installation instructions

VERDER CARBOLITE GERO ABF 8/28 Installation, operation and maintenance instructions

VERDER

VERDER CARBOLITE GERO ABF 8/28 Installation, operation and maintenance instructions

Goodman GMV9 Installation & operating instructions

Goodman

Goodman GMV9 Installation & operating instructions

SUPREME SUP10-M2301C Installation instructions and homeowner's manual

SUPREME

SUPREME SUP10-M2301C Installation instructions and homeowner's manual

Dettson AMT400B34-SM1PMA Installation instructions and homeowner's manual

Dettson

Dettson AMT400B34-SM1PMA Installation instructions and homeowner's manual

Evcon DGD 60 MBH installation instructions

Evcon

Evcon DGD 60 MBH installation instructions

Trane S8B1A026M2PSAB Installer's guide

Trane

Trane S8B1A026M2PSAB Installer's guide

Hart Sceintific 9113 user manual

Hart Sceintific

Hart Sceintific 9113 user manual

Whirlpool Gold WGGE45 installation instructions

Whirlpool

Whirlpool Gold WGGE45 installation instructions

https://manuals.online logo
https://manuals.online logoBrands
  • About & Mission
  • Contact us
  • Privacy Policy
  • Terms and Conditions

Copyright 2026 Manuals.Online. All Rights Reserved.

G40
Mid-efficiency gas furnace
Home Comfort Systems
LENNOX’ MERIT®SERIES
G40 Gas Furnace ◆80% AFUE
Mid-efficiency levels save
you money, compared to
older furnaces
Durable, high-quality design
for long-lasting performance
Merit®Series G40 Gas Furnace
EFFICIENT, CONSISTENT WARMTH—YEAR AFTER YEAR
G40
80% AFUE
Innovation never felt so good.
™
EFFICIENCY RATING
80% AFUE (Annual Fuel
Utilization Efficiency)
WARRANTY*
20-year limited warranty
on the heat exchanger.
5-year limited warranty
on all remaining
covered components.
© Lennox Industries Inc. 2002
Visit us at www.lennox.com, or contact us at 1-800-9-LENNOX.
(37M96) G40 2/07
PC48540
Merit®Series G40 Specifications
UH36A-045
G40 UH24A-045 (X) UH24A-070 UH36A-070 UH36B-090 UH36C-110 UH48B-070 UH48B-090 (X)
AFUE 80% 80% 80% 80% 80% 80% 80%
Dimensions HxWxD (in.) 40 x 14-1/2 x 28-1/2 40 x 14-1/2 x 28-1/2 40 x 14-1/2 x 28-1/2 40 x 17-1/2 x 28-1/2 40 x 21 x 28-1/2 40 x 17-1/2 x 28-1/2 40 x 17-1/2 x 28-1/2
HxWxD (mm) 1016 x 368 x 724 1016 x 368 x 724 1016 x 368 x 724 1016 x 446 x 724 1016 x 533 x 724 1016 x 446 x 724 1016 x 446 x 724
G40 UH48C-110 UH60C-110 (X) UH48C-135 UH60D-135 UH60D-155 DF-24A-045 (X) DF-36A-045
AFUE 80% 80% 80% 80% 80% 80% 80%
Dimensions HxWxD (in.) 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 40 x 24-1/2 x 28-1/2 40 x 14-1/2 x 28-1/2 40 x 14-1/2 x 28-1/2
HxWxD (mm) 1016 x 533 x 724 1016 x 533 x 724 1016 x 533 x 724 1016 x 622 x 724 1016 x 622 x 724 1016 x 368 x 724 1016 x 368 x 724
G40 DF-36A-070 (X) DF-36B-090 DF-48B-070 DF-48C-090 (X) DF-48C-110 (X) DF-60C-110 (X) DF-60D-135
AFUE 80% 80% 80% 80% 80% 80% 80%
Dimensions HxWxD (in.) 40 x 14-1/2 x 28-1/2 40 x 17-1/2 x 28-1/2 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 368 x 724 1016 x 446 x 724 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.
THIS MODEL
80%
Lennox is proud of the
fact that these products
have earned the Good
Housekeeping Seal.
Year-round comfort – Built to
deliver outstanding comfort,
year after year.
Duralok®Heat Exchanger –
Made of high-quality, patented
ArmorTuf™aluminized steel.
Life-tested to 2-1/2 times agency
requirements (ANSI Standard
Z21.47) for long product life
and durability.
Hot Surface Igniter – Delivers
starting reliability.
Durable Steel Cabinet –
Constructed of heavy-gauge steel
and protected by a high-quality,
textured-paint finish.
*Applies to residential applications only.
See actual warranty certificate for details.