Lennox MERIT ML180UHE User Manual

Page 1
06/11
*2P0611*
506810−01
*P506810-01*
 2011 Lennox Industries Inc.
Dallas, Texas, USA
AIR FLOW
UPFLOW
AIR FLOW
AIR FLOW
HORIZONTAL RIGHT
HORIZONTAL LEFT
INSTALLATION
INSTRUCTIONS
ML180UHE
MERIT
®
SERIES GAS FURNACE
UPFLOW / HORIZONTAL AIR DISCHARGE
506810−01
06/2011
Supersedes 506732−01
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 manuals, be alert
to the potential for personal injury or death.
WARNING
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, person-
al injury or loss of life. Installation and service must
be performed by a licensed professional installer (or
equivalent), service agency or the gas supplier.
CAUTION
As with any mechanical equipment, personal injury
can result from contact with sharp sheet metal
edges. Be careful when you handle this equipment.
Table of Contents
Unit Dimensions 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Arrangement 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ML180UHE Gas Furnace 4. . . . . . . . . . . . . . . . . . . . . . . . .
Shipping and Packing List 4. . . . . . . . . . . . . . . . . . . . . . . .
Safety Information 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Use of Furnace as a Construction Heater 5. . . . . . . . . . .
General 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Combustion, Dilution & Ventilation Air 6. . . . . . . . . . . . . .
Setting Equipment 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Filters 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Duct System 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Venting 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gas Piping 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrical 25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Integrated Control 28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unit Start−Up 29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gas Pressure Adjustment 30. . . . . . . . . . . . . . . . . . . . . . . .
High Altitude 30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Proper Combustion 30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other Unit Adjustments 31. . . . . . . . . . . . . . . . . . . . . . . . . .
Blower Performance Data 33. . . . . . . . . . . . . . . . . . . . . . . .
Service 35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Planned Service 37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Repair Parts List 37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Integrated Control Diagnostic Codes 38. . . . . . . . . . . . . . .
Troubleshooting 39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Litho U.S.A.

Lennox MERIT ML180UHE Specifications

General

Brand	Lennox
Model	MERIT ML180UHE
Category	Furnace
Language	English

Summary

Unit Dimensions and Parts

Parts Arrangement

Diagram illustrating the location of key furnace components.

Shipping and Packing List

List of items included with the furnace shipment and separately ordered items.

Safety and Installation Requirements

General Safety Warnings

Essential safety warnings and cautions for furnace operation and handling.

Combustion Air Requirements

Hazards and requirements for providing adequate combustion and ventilation air.

Installation Clearances

Specific clearance requirements for upflow and horizontal furnace installations.

Venting and Gas Piping

Horizontal Application Installation

Procedures for installing the furnace in horizontal applications, including suspension.

Venting System Installation

Instructions for connecting the vent pipe, ensuring proper draft, and safety warnings.

Gas Piping Installation

Guidelines for gas supply piping, including pressure drop, pipe sizing, and installation practices.

Electrical, Controls, and Operation

Electrical Connections and Wiring

Procedures for electrical connections, ESD precautions, and wiring diagrams.

Thermostat and Start-Up Procedure

Instructions for thermostat installation and the step-by-step guide for safely starting the furnace.

Sequence of Operation

Step-by-step explanation of the furnace's heating and blower operation sequence.

Performance Tuning and Maintenance

Performance Adjustments and Checks

Procedures for adjusting gas pressure, combustion, temperature rise, and blower settings.

Service and Planned Maintenance

Procedures for annual inspection, cleaning, and servicing of furnace components.

Repair Parts List

List of available replacement parts for the furnace.

Troubleshooting and Diagnostics

Integrated Control Diagnostics

Explanation of error codes indicated by the furnace's integrated control LED.

Troubleshooting Guides

Flowcharts and guidance for diagnosing and resolving operational issues.

Final Checks and Operation

Start-Up & Performance Check List

A checklist to verify proper installation and initial setup of the furnace.

Unit Operation Verification

Checks for verifying furnace operation parameters during heating and cooling modes.