Lennox International Inc. MERIT SERIES GAS FURNACE DOWNFLOW AIR DISCHARGE User Manual
Page 1
01/11
*2P0111*
506475−01
*P506475-01*
2010 Lennox Industries Inc.
Dallas, Texas, USA
AIR FLOW
DOWNFLOW
INSTALLATION
INSTRUCTIONS
ML193DF
INSTRUCTIONS
ML193DF
MERIT
®
SERIES GAS FURNACE
DOWNFLOW AIR DISCHARGE
506475−01
01/2011
Supersedes 10/2010
01/2011
Supersedes 10/2010
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.
When you see this symbol on labels or in manuals, be alert
to the potential for personal injury or death.
CAUTION
As with any mechanical equipment, personal injury
can result from contact with sharp sheet metal
edges. Be careful when you handle this equipment.
can result from contact with sharp sheet metal
edges. Be careful when you handle this equipment.
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.
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.
Table of Contents
Unit Dimensions
2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ML193DF Parts Arrangement
3
. . . . . . . . . . . . . . . . . . . . .
ML193DF Gas Furnace
4
. . . . . . . . . . . . . . . . . . . . . . . . . .
Shipping and Packing List
4
. . . . . . . . . . . . . . . . . . . . . . . .
Safety Information
4
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Use of Furnace as a Construction Heater
5
. . . . . . . . . . .
General
6
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Combustion, Dilution and Ventilation Air
6
. . . . . . . . . . . .
Setting Equipment
9
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Filters
12
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Duct System
12
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pipe and Fittings Specifications
12
. . . . . . . . . . . . . . . . . . .
Joint Cementing Procedure
14
. . . . . . . . . . . . . . . . . . . . . .
Venting Practices
14
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vent Piping Guidelines
15
. . . . . . . . . . . . . . . . . . . . . . . . . .
Gas Piping
30
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrical
32
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unit Start Up
36
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gas Pressure Measurement
38
. . . . . . . . . . . . . . . . . . . . .
Proper Combustion
38
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
High Altitude
38
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Testing Non Direct Appliances for Proper Air
39
. . . . . . .
Other Unit Adjustments
40
. . . . . . . . . . . . . . . . . . . . . . . . . .
Blower Motor Performance
41
. . . . . . . . . . . . . . . . . . . . . . .
Service
42
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Planned Service
44
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Integrated Control Diagnostic Codes
44
. . . . . . . . . . . . . .
Troubleshooting
45
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Repair Parts List
49
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Start Up Checklist
50
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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