Lennox ML16XP1 Series Unit Information

Service Literature
ML16XP1 (HFC- 410A) SERIES OUTDOOR UNITS
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.
IMPORTANT
The Clean Air Act of 1990 bans the intentional venting of
refrigerant (CFCs, HCFCs and HFCs) as of July 1, 1992.
Approved methods of recovery, recycling or reclaiming
must be followed. Fines and/or incarceration may be
levied for noncompliance.
IMPORTANT
This unit must be matched with an indoor coil as specified
with AHRI. For AHRI Certified system matchups and
expanded ratings, visit www.LennoxPros.com. Coils
previously charged with HCFC-22 must be flushed.
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.
WARNING
Electric Shock Hazard. Can cause injury or
death. Unit must be properly grounded in
accordance with national and local codes.
Line voltage is present at all components when
unit is not in operation on units with single-
pole contactors. Disconnect all remote electric
power supplies before opening access panel.
Unit may have multiple power supplies.
UNIT INFORMATION
Corp. 1818-L8
March 3, 2020

Table of Contents

Installation Clearances ...................................................2
Model Number Identification ...........................................2
Dimensions .....................................................................3
Specifications .................................................................4
Typical Unit Parts Arrangement ......................................6
Operating Gauge Set and Service Valves ......................6
Unit Placement ..............................................................8
Removing and Installing Louvered Panels .....................9
New or Replacement Line Set ......................................10
Brazing Connections ...................................................12
Flushing Line Set and Indoor Coil ................................15
Installing Indoor Metering Device .................................16
Leak Test Line Set and Indoor Coil ..............................17
Evacuating Line Set and Indoor Coil ...........................18
Electrical .......................................................................19
System Operation .......................................................21
System Configuration ...................................................21
Defrost System ...........................................................24
Maintenance ...............................................................26
Wiring and Sequence of Operation
Servicing Units Void of Charge ...................................32
Start-Up ......................................................................32
General Information
These instructions are intended as a general guide and do
not supersede national or local codes in any way. Consult
authorities having jurisdiction before installation.
The Merit® ML16XP1 model is designed for use with
HFC-410A refrigerant only. This unit must be installed with
an approved indoor air handler or coil. For AHRI Certified
system matchups and expanded ratings, visit www.Len-
noxPros.com.
This outdoor unit is designed for use in systems that use
the following refrigerant metering device:
• Check thermal expansion valve (CTXV)
IMPORTANT: Special procedures are required for clean-
ing the all-aluminum coil in this unit. See page 26 in this
instruction for information.
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ML16XP1
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