Lennox ML196UH070XE36B

Page 1
INSTALLATION
INSTRUCTIONS
ML196UHE
507966-04
04/2021
Supersedes 507966-03
THIS MANUAL MUST BE LEFT WITH THE
HOMEOWNER FOR FUTURE REFERENCE
This is a safety alert symbol and should never be
ignored. When you see this symbol on labels or in man-
uals, be alert to the potential for personal injury or death.
WARNING
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, personal
injury or loss of life. Installation and service must be
performed by a licensed professional HVAC installer (or
equivalent), service agency or the gas supplier.
CAUTION
As with any mechanical equipment, contact with sharp
sheet metal edges can result in personal injury. Take
care while handling this equipment and wear gloves and
protective clothing.
© 2021 Lennox Industries Inc.
Dallas, Texas USA
MERIT
®
SERIES GAS FURNACE
UPFLOW / HORIZONTAL AIR DISCHARGE
Contents
Unit Dimensions - inches (mm) ......................................2
ML196UHE .....................................................................3
Shipping and Packing List ..............................................3
Safety .............................................................................3
Use of Furnace as a Construction Heaterl .....................4
General ...........................................................................5
Combustion, Dilution, Ventilation Air...............................5
Setting Equipment ..........................................................8
Filters ............................................................................13
Duct System .................................................................13
Pipe Fittings Specications...........................................13
Joint Cementing Procedure .......................................... 16
Venting Practices ..........................................................16
Gas Piping ....................................................................36
Electrical .......................................................................39
Unit Start-Up .................................................................42
Gas Pressure Measurement.........................................44
Proper Combustion.......................................................44
High Altitude .................................................................44
Testing Combustion Air For Non-Dierct Vent ................ 46
Other Unit Adjustments.................................................46
Service..........................................................................48
Repair Parts List ...........................................................49
Start-Up Checklist.........................................................51
Blower Data ..................................................................53

Lennox ML196UH070XE36B Specifications

General

Brand	Lennox
Model	ML196UH070XE36B
Category	Furnace
Language	English

Summary

Safety and Identification

Unit Identification and Contents

Identifies the furnace model and lists manual contents.

General Safety Warnings

Crucial warnings regarding installation, adjustment, and maintenance.

Electrical Safety Precautions

Precautions for handling electrical components and preventing shock.

Unit Specifications and Installation

Unit Dimensions and Components

Details physical dimensions, packing list, and repair parts.

Installation Locations and Clearances

Specifies acceptable locations, clearances, and construction heater use.

Venting and Piping Specifications

Details approved materials and standards for vent pipe and fittings.

Gas Piping Installation

Procedures for connecting the gas supply line to the furnace.

Operation and Performance

Unit Start-Up Procedures

Step-by-step guide for initial furnace operation and testing.

Gas Flow, Pressure, and Combustion Checks

Procedures for measuring gas flow, pressure, and checking combustion.

Venting and Combustion Air Testing

Procedures for ensuring proper venting and combustion air supply.

Blower Data and Speed Settings

Tables detailing air volume, wattage, and speed settings.

Maintenance and Service

Service Precautions

Critical warnings and procedures before performing service.

Annual Furnace Maintenance Checklist

Recommended checks and maintenance tasks for each heating season.

Burner Assembly Cleaning Procedure

Step-by-step instructions for cleaning the furnace burners.