Lennox ML16XP1 Series Outdoor Units

Safety Information

⚠️ 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.

Table of Contents

• Installation Clearances - Page 2
• Model Number Identification - Page 2
• Dimensions - Page 3
• Specifications - Page 4
• Typical Unit Parts Arrangement - Page 6
• Operating Gauge Set and Service Valves - Page 6
• Unit Placement - Page 8
• Removing and Installing Louvered Panels - Page 9
• New or Replacement Line Set - Page 10
• Brazing Connections - Page 12
• Flushing Line Set and Indoor Coil - Page 15
• Installing Indoor Metering Device - Page 16
• Leak Test Line Set and Indoor Coil - Page 17
• Evacuating Line Set and Indoor Coil - Page 18
• Electrical - Page 19
• System Operation - Page 21
• System Configuration - Page 21
• Defrost System - Page 24
• Maintenance - Page 26
• Wiring and Sequence of Operation - Page 28
• Servicing Units Void of Charge - Page 32
• Start-Up - Page 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.LennoxPros.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 cleaning the all-aluminum coil in this unit. See page 26 in this instruction for information.

Installation Clearances

Diagram shows a top view of the outdoor unit with clearance zones indicated by arrows and labels like 'See NOTES' and 'CONTROL BOX'.

NOTES:

• Service clearance of 30 in. (762 mm) must be maintained on one of the sides adjacent to the control box.
• Clearance to one of the other three sides must be 36 in. (914 mm).
• Clearance to one of the remaining two sides may be 12 in. (305 mm) and the final side may be 6 in. (152 mm).
• A clearance of 24 in. must be maintained between two units.
• 48 in. (1219 mm) clearance required on top of unit.

Model Number Identification

Diagram illustrates the ML16XP1 model number breakdown: ML 16 X P1 - 036 - 230 A 0 1.

• Product Tier: ML = Merit® Series
• Nominal SEER: (Not specified in diagram, implied by model number)
• Refrigerant Type: X = R-410A
• Unit Type: P = Heat Pump Outdoor Unit
• Cooling Stages: 1 = Single Stage Compressor
• Revision Level: (Not specified in diagram)
• Ratings Revision Level: (Not specified in diagram)
• Voltage: 230 = 208/230V-1 phase-60hz
• Nominal Cooling Capacity:
  • 018 = 1.5 tons
  • 024 = 2 tons
  • 030 = 2.5 tons
  • 036 = 3 tons
  • 042 = 3.5 tons
  • 048 = 4 tons
  • 060 = 5 tons

Dimensions

Diagrams show Top View, Top View Base Section, and Side Views of the outdoor unit, indicating inlet air, discharge air, connections, and overall dimensions.

Top View Base Section shows mounting hole locations and dimensions.

Side Views show overall dimensions A, B, and C.

Specifications

General Data

Electrical Data

Specifications (Continued)

Optional Accessories - Order Separately

NOTE - Extremes of operating range are plus 10% and minus 5% of line voltage.

1 Sound Rating Number rated in accordance with test conditions included in AHRI Standard 270.

2 Refrigerant charge sufficient for 15 ft. length of refrigerant lines. For longer line set requirements see the Installation Instructions for information about line set length and additional refrigerant charge required.

3 HACR type breaker or fuse.

4 Refer to National or Canadian Electrical Code manual to determine wire, fuse and disconnect size requirements.

5 Crankcase Heater and Freezestat are recommended with Low Ambient Kit

Typical Unit Parts Arrangement

Diagram shows a typical plumbing arrangement for the outdoor unit, labeling components such as CHECK / EXPANSION VALVE, BI-FLOW FILTER DRIER, HIGH PRESSURE SWITCH, LIQUID LINE SERVICE VALVE, DISCHARGE LINE, LOW PRESSURE SWITCH, REVERSING VALVE, and VAPOR LINE SERVICE VALVE.

Operating Gauge Set and Service Valves

Torque Requirements

When servicing or repairing heating, ventilating, and air conditioning components, ensure the fasteners are appropriately tightened. Table 1 lists torque values for fasteners.

❗ IMPORTANT: Only use Allen wrenches of sufficient hardness (50Rc - Rockwell Harness Scale minimum). Fully insert the wrench into the valve stem recess. Service valve stems are factory-torqued (from 9 ft-lbs for small valves, to 25 ft-lbs for large valves) to prevent refrigerant loss during shipping and handling. Using an Allen wrench rated at less than 50Rc risks rounding or breaking off the wrench, or stripping the valve stem recess. See the Lennox Service and Application Notes #C-08-1 for further details and information.

❗ IMPORTANT: To prevent stripping of the various caps used, the appropriately sized wrench should be used and fitted snugly over the cap before tightening.

Using Manifold Gauge Set

When checking the system charge, only use a manifold gauge set that features low loss anti-blow back fittings. Manifold gauge set used with HFC-410A refrigerant systems must be capable of handling the higher system operating pressures. The gauges should be rated for use with pressures of 0 - 800 psig on the high side and a low side of 30" vacuum to 250 psig with dampened speed to 500 psi. Gauge hoses must be rated for use at up to 800 psig of pressure with a 4000 psig burst rating.

Operating Service Valves

The liquid and vapor line service valves are used for removing refrigerant, flushing, leak testing, evacuating, checking charge and charging. Each valve is equipped with a service port which has a factory-installed valve stem. Figure 2 provides information on how to access and operate both angle and ball service valves.

Service Valves: Angle and Ball

Operating Angle Type Service Valve

1. Remove stem cap with an appropriately sized wrench.
2. Use a service wrench with a hex-head extension (3/16" for liquid line valve sizes and 5/16" for vapor line valve sizes) to back the stem out counterclockwise as far as it will go.

Diagram shows an angle-type service valve, illustrating the stem cap, service port core, and valve stem positions (OPEN/BACK-SEATED and CLOSED/FRONT-SEATED).

Operating Ball Type Service Valve

1. Remove stem cap with an appropriately sized wrench.
2. Use an appropriately sized wrench to open. To open valve, rotate stem counterclockwise 90°. To close rotate stem clockwise 90°.

Diagram shows a ball-type service valve, illustrating the stem cap, service port core, valve stem, and ball, with indicators for opening and closing directions.

To Access Service Port

A service port cap protects the service port core from contamination and serves as the primary leak seal.

1. Remove service port cap with an appropriately sized wrench.
2. Connect gauge set to service port.
3. When testing is completed, replace service port cap and tighten as follows:
   • With torque wrench: Finger tighten and torque cap per table 3.
   • Without torque wrench: Finger tighten and use an appropriately sized wrench to turn an additional 1/6 turn clockwise.

Reinstall Stem Cap

Stem cap protects the valve stem from damage and serves as the primary seal. Replace the stem cap and tighten as follows:

• With Torque Wrench: Finger tighten and then torque cap per table 3.
• Without Torque Wrench: Finger tighten and use an appropriately sized wrench to turn an additional 1/12 turn clockwise.

NOTE - A label with specific torque requirements may be affixed to the stem cap. If the label is present, use the specified torque.

Unit Placement

Diagrams show placement considerations: Detail A illustrates installing the unit away from windows. Detail B shows installing the unit level or with a specific slope tolerance away from a building structure, with a note about two 90° elbows reducing line set vibration.

See Unit Dimensions on page 3 for sizing mounting slab, platforms or supports. Refer to page 2 for mandatory installation clearance requirements.

? CAUTION: In order to avoid injury, take proper precaution when lifting heavy objects.

Positioning Considerations

• Some localities are adopting sound ordinances based on the unit's sound level registered from the adjacent property, not from the installation property. Install the unit as far as possible from the property line.
• When possible, do not install the unit directly outside a window. Glass has a very high level of sound transmission. For proper placement of unit in relation to a window see the provided illustration in figure 3, detail A.

Placing Unit on Slab

When installing unit at grade level, the top of the slab should be high enough above grade so that water from higher ground will not collect around the unit. The slab should have a slope tolerance as described in figure 3, detail B.

Roof Mounting

Install the unit a minimum of 6 inches (152 mm) above the roof surface to avoid ice build-up around the unit. Locate the unit above a load bearing wall or area of the roof that can adequately support the unit. Consult local codes for rooftop applications.

If unit coil cannot be mounted away from prevailing winter winds, a wind barrier should be constructed. Size barrier at least the same height and width as outdoor unit. Mount barrier 24 inches (610 mm) from the sides of the unit in the direction of prevailing winds.

NOTICE: Roof Damage! This system contains both refrigerant and oil. Some rubber roofing material may absorb oil, causing the rubber to swell. Bubbles in the rubber roofing material can cause leaks. Protect the roof surface to avoid exposure to refrigerant and oil during service and installation. Failure to follow this notice could result in damage to roof surface.

Removing and Installing Louvered Panels

⚠️ WARNING: To prevent personal injury, or damage to panels, unit or structure, be sure to observe the following: While installing or servicing this unit, carefully stow all removed panels out of the way, so that the panels will not cause injury to personnel, nor cause damage to objects or structures nearby, nor will the panels be subjected to damage (e.g., being bent or scratched). While handling or stowing the panels, consider any weather conditions, especially windy conditions, that may cause panels to be blown around and battered.

Diagram shows steps for REMOVAL: Step 1 - Remove mounting screws. Step 2 - Lift panel to clear side lips. Step 3 - Tilt panel out and pull downward. Diagram shows steps for PANEL INSTALLATION: Step 1 - Insert panel under top cap lip and lift. Step 2 - Align panel lips with groove inserts. Step 3 - Secure with mounting screws. Labels identify PANEL CENTER, CORNER POST, PANEL LEFT, PANEL RIGHT, TOP CAP, BASE, and SIDE GROOVE.

New or Replacement Line Set

This section provides information on new installation or replacement of existing line set. If a new or replacement line set is not required, then proceed to Brazing Connections on page 12.

If refrigerant lines are routed through a wall, seal and isolate the opening so vibration is not transmitted to the building. Pay close attention to line set isolation during installation of any HVAC system. When properly isolated from building structures (walls, ceilings, floors), the refrigerant lines will not create unnecessary vibration and subsequent sounds.

Refrigerant Line Set

Field refrigerant piping consists of liquid and suction lines from the outdoor unit (braze connections) to the indoor unit coil (flare or braze connections). Use Lennox L15 (braze, non-flare) series line set, or use field-fabricated refrigerant lines as listed in table 2.

NOTE - Some applications may require a field-provided 7/8" to 1-1/8" adapter.

NOTE – When installing refrigerant lines longer than 50 feet, contact Lennox Technical Support Product Applications for assistance or Lennox piping manual. To obtain the correct information from Lennox, be sure to communicate the following points:

• Model (ML16XP1) and size of unit (e.g. -060).
• Line set diameters for the unit being installed as listed in table 2 and total length of installation.
• Number of elbows and if there is a rise or drop of the piping.

❗ IMPORTANT: Mineral oils are not compatible with HFC-410A. If oil must be added, it must be a Polyol ester oil.

The compressor is charged with sufficient Polyol ester oil for line set lengths up to 50 feet. Recommend adding oil to system based on the amount of refrigerant charge in the system. No need to add oil in system with 20 pounds of refrigerant or less. For systems over 20 pounds - add one ounce for every five pounds of refrigerant.

Recommended topping-off POE oils are Mobil EAL ARCTIC 22 CC or ICI EMKARATE RL32CF.

Matching With New or Existing Indoor Coil and Line Set

The RFC1-metering line consisted of a small bore copper line that ran from condenser to evaporator coil. Refrigerant was metered into the evaporator by utilizing temperature/pressure evaporation effects on refrigerant in the small RFC line. The length and bore of the RFC line corresponded to the size of cooling unit. If the ML16XP1 is being used with either a new or existing indoor coil which is equipped with a liquid line which served as a metering device (RFCI), the liquid line must be replaced prior to the installation of the ML16XP1 unit. Typically a liquid line used to meter flow is 1/4” in diameter and copper.

Line Set Isolation

? CAUTION: Brazing alloys and flux contain materials which are hazardous to your health. Avoid breathing vapors or fumes from brazing operations. Perform operations only in well-ventilated areas. Wear gloves and protective goggles or face shield to protect against burns. Wash hands with soap and water after handling brazing alloys and flux.

❗ IMPORTANT: The Clean Air Act of 1990 bans the intentional venting of refrigerant (CFC's and HCFC's) as of July 1, 1992. Approved methods of recovery, recycling or reclaiming must be followed. Fines and/or incarceration may be levied for non-compliance.

❗ IMPORTANT: If this unit is being matched with an approved line set or indoor unit coil that was previously charged with mineral oil, or if it is being matched with a coil which was manufactured before January of 1999, the coil and line set must be flushed prior to installation. Take care to empty all existing traps. Polyol ester (POE) oils are used in Lennox units charged with HFC-410A refrigerant. Residual mineral oil can act as an insulator, preventing proper heat transfer. It can also clog the expansion device and reduce system performance and capacity. Failure to properly flush the system, per this instruction and the detailed Installation and Service Procedures manual will void the warranty.

Line Set Installation

❗ IMPORTANT: Refrigerant lines must not contact structure.

Line Set Isolation

The following illustrations are examples of proper refrigerant line set isolation:

Diagram shows REFRIGERANT LINE SET - TRANSITION FROM VERTICAL TO HORIZONTAL, illustrating anchors, hangers, sleeves, and line wrapping.

Diagram shows REFRIGERANT LINE SET - INSTALLING VERTICAL RUNS (NEW CONSTRUCTION SHOWN), illustrating wall structure, wire ties, sleeves, and line wrapping. Includes a note about insulating the liquid line.

❗ IMPORTANT: Refrigerant lines must not contact wall.

Diagram shows REFRIGERANT LINE SET - INSTALLING HORIZONTAL RUNS, illustrating hanging from joists/rafters with strapping or wire ties, sleeves, and line wrapping.

⚠️ WARNING: Polyol ester (POE) oils used with HFC-410A refrigerant absorb moisture very quickly. It is very important that the refrigerant system be kept closed as much as possible. DO NOT remove line set caps or service valve stub caps until you are ready to make connections.

Brazing Connections

Use the procedures outlined in figures 6 and 7 for brazing line set connections to service valves.

⚠️ WARNING: Danger of fire. Bleeding the refrigerant charge from only the high side may result in pressurization of the low side shell and suction tubing. Application of a brazing torch to a pressurized system may result in ignition of the refrigerant and oil mixture. Check the high and low pressures before applying heat.

⚠️ WARNING: When using a high pressure gas such as nitrogen to pressurize a refrigeration or air conditioning system, use a regulator that can control the pressure down to 1 or 2 psig (6.9 to 13.8 kPa).

? CAUTION: Brazing alloys and flux contain materials which are hazardous to your health. Avoid breathing vapors or fumes from brazing operations. Perform operations only in well-ventilated areas. Wear gloves and protective goggles or face shield to protect against burns. Wash hands with soap and water after handling brazing alloys and flux.

❗ IMPORTANT: Allow braze joint to cool before removing the wet rag from the service valve. Temperatures above 250°F can damage valve seals.

❗ IMPORTANT: Use silver alloy brazing rods with 5% minimum silver alloy for copper-to-copper brazing. Use 45% minimum alloy for copper-to-brass and copper-to-steel brazing.

⚠️ WARNING: Fire, Explosion and Personal Safety hazard. Failure to follow this warning could result in damage, personal injury or death. Never use oxygen to pressurize or purge refrigeration lines. Oxygen, when exposed to a spark or open flame, can cause fire and/ or an explosion, that could result in property damage, personal injury or death.

Brazing Procedures

Figure 6 illustrates brazing procedures. It includes steps for CUT AND DEBUR, CAP AND CORE REMOVAL, and ATTACH THE MANIFOLD GAUGE SET.

Step 1: CUT AND DEBUR

Cut ends of the refrigerant lines square (free from nicks or dents) and debur the ends. The pipe must remain round. Do not crimp end of the line.

Step 2: CAP AND CORE REMOVAL

Remove service cap and core from both the suction / vapor and liquid line service ports.

Step 3: ATTACH THE MANIFOLD GAUGE SET FOR BRAZING LIQUID AND SUCTION / VAPOR LINE SERVICE VALVES

Flow regulated nitrogen (at 1 to 2 psig) through the low-side refrigeration gauge set into the liquid line service port valve, and out of the suction / vapor line service port valve.

1. Connect gauge set low pressure side to liquid line service valve (service port).
2. Connect gauge set center port to bottle of nitrogen with regulator.
3. Remove core from valve in suction / vapor line service port to allow nitrogen to escape.

Diagram shows the gauge set connections for brazing, including nitrogen cylinder, regulator, manifold gauge set, and service valves.

Figure 7 continues the Brazing Procedures.

Step 4: WRAP SERVICE VALVES

To help protect service valve seals during brazing, wrap water saturated cloths around service valve bodies and copper tube stubs. Use additional water saturated cloths underneath the valve body to protect the base paint.

Step 5: FLOW NITROGEN

Flow regulated nitrogen (at 1 to 2 psig) through the refrigeration gauge set into the valve stem port connection on the liquid service valve and out of the suction / vapor valve stem port. See steps 3A, 3B and 3C on manifold gauge set connections.

Step 6: BRAZE LINE SET

Wrap both service valves with water saturated cloths as illustrated here and as mentioned in step 4, before brazing to line set. Water saturated cloths must remain water saturated throughout the brazing and cool-down process.

Diagram shows brazing the line set to service valves, with water saturated cloths applied for protection.

❗ IMPORTANT: Allow braze joint to cool. Apply additional water saturated cloths to help cool brazed joint. Do not remove water saturated cloths until piping has cooled. Temperatures above 250°F will damage valve seals.

⚠️ WARNING: 1. FIRE, PERSONAL INJURY, OR PROPERTY DAMAGE may result if you do not wrap a water saturated cloth around both liquid and suction line service valve bodies and copper tube stub while brazing in the line set! The braze, when complete, must be quenched with water to absorb any residual heat. 2. Do not open service valves until refrigerant lines and indoor coil have been leak-tested and evacuated. Refer to procedures provided in this supplement.

Step 7: PREPARATION FOR NEXT STEP

After all connections have been brazed, disconnect manifold gauge set from service ports. Apply additional water saturated cloths to both services valves to cool piping. Once piping is cool, remove all water saturated cloths. Refer to the unit installation instructions for the next step in preparing the unit.

Flushing Line Set and Indoor Coil

Figure 8 illustrates removing metering devices and flushing. It shows procedures for TYPICAL EXISTING FIXED ORIFICE REMOVAL (1A) and TYPICAL EXISTING EXPANSION VALVE REMOVAL (1B).

Step 2: CONNECT GAUGES AND EQUIPMENT FOR FLUSHING PROCEDURE

Diagram shows the setup for flushing, including an inverted HCFC-22 cylinder, gauge manifold, recovery machine, and indoor/outdoor units.

Step 3: FLUSHING LINE SET

The line set and indoor unit coil must be flushed with at least the same amount of clean refrigerant* that previously charged the system. Check the charge in the flushing cylinder before proceeding.

1. Set the recovery machine for liquid recovery and start the recovery machine. Open the gauge set valves to allow the recovery machine to pull a vacuum on the existing system line set and indoor unit coil.
2. Invert the cylinder of clean HCFC-22* and open its valve to allow liquid refrigerant to flow into the system through the vapor line valve. Allow the refrigerant to pass from the cylinder and through the line set and the indoor unit coil before it enters the recovery machine.
3. After all of the liquid refrigerant has been recovered, switch the recovery machine to vapor recovery so that all of the HCFC-22 vapor is recovered. Allow the recovery machine to pull the system down to 0.
4. Close the valve on the inverted HCFC-22 drum and the gauge set valves. Pump the remaining refrigerant out of the recovery machine and turn the machine off.

❗ IMPORTANT: Clean refrigerant is any refrigerant in a system that has not had compressor burn out. If the system has experienced burn out, it is recommended that the existing line set and indoor coil be replaced.

Installing Indoor Metering Device

This outdoor unit is designed for use in systems that use a check / expansion valve metering device at the indoor coil. See the Lennox ML16XP1 Product Specification bulletin for approved expansion valve kit match-ups. The expansion valve unit can be installed internal or external to the indoor coil.

In applications where an uncased coil is being installed in a field-provided plenum, install the expansion valve in a manner that will provide access for field servicing of the expansion valve. Refer to below illustration for reference during installation of expansion valve unit.

Figure 9 shows INDOOR EXPANSION VALVE INSTALLATION, EQUALIZER LINE INSTALLATION, and SENSING BULB INSTALLATION with detailed steps and diagrams.

Indoor Expansion Valve Installation Steps:

1. Remove the field-provided fitting that temporarily reconnected the liquid line to the indoor unit's distributor assembly.
2. Install one of the provided Teflon® rings around the stubbed end of the expansion valve and lightly lubricate the connector threads and expose surface of the Teflon® ring with refrigerant oil.
3. Attach the stubbed end of the expansion valve to the liquid line orifice housing. Finger tighten and use an appropriately sized wrench to turn an additional 1/2 turn clockwise as illustrated in the figure above, or 20 ft-lb.
4. Place the remaining Teflon® washer around the other end of the expansion valve. Lightly lubricate connector threads and expose surface of the Teflon® ring with refrigerant oil.
5. Attach the liquid line assembly to the expansion valve. Finger tighten and use an appropriately sized wrench to turn an additional 1/2 turn clockwise as illustrated in the figure above or 20 ft-lb.

Sensing Bulb Installation Steps:

1. Attach the vapor line sensing bulb in the proper orientation as illustrated to the right using the clamp and screws provided.
2. Connect the equalizer line from the expansion valve to the equalizer vapor port on the vapor line. Finger tighten the flare nut plus 1/8 turn (7 ft-lbs) as illustrated below.

NOTE - Confirm proper thermal contact between vapor line and expansion bulb before insulating the sensing bulb once installed.

Equalizer Line Installation Steps:

1. Remove and discard either the flare seal cap or flare nut with copper flare seal bonnet from the equalizer line port on the vapor line as illustrated in the figure to the right.
2. Remove and discard either the flare seal cap or flare nut with copper flare seal bonnet from the equalizer line port on the vapor line as illustrated in the figure to the right.

NOTE - NEVER MOUNT ON BOTTOM OF LINE.

Leak Test Line Set and Indoor Coil

❗ IMPORTANT: The Clean Air Act of 1990 bans the intentional venting of refrigerant (CFC's and HCFC's) as of July 1, 1992. Approved methods of recovery, recycling or reclaiming must be followed. Fines and/or incarceration may be levied for non-compliance.

❗ IMPORTANT: If this unit is being matched with an approved line set or indoor unit coil that was previously charged with mineral oil, or if it is being matched with a coil which was manufactured before January of 1999, the coil and line set must be flushed prior to installation. Take care to empty all existing traps. Polyol ester (POE) oils are used in Lennox units charged with HFC-410A refrigerant. Residual mineral oil can act as an insulator, preventing proper heat transfer. It can also clog the expansion device and reduce system performance and capacity. Failure to properly flush the system, per this instruction and the detailed Installation and Service Procedures manual will void the warranty.

⚠️ WARNING: When using a high pressure gas such as nitrogen to pressurize a refrigeration or air conditioning system, use a regulator that can control the pressure down to 1 or 2 psig (6.9 to 13.8 kPa).

❗ IMPORTANT: Leak detector must be capable of sensing HFC refrigerant.

⚠️ WARNING: Refrigerant can be harmful if it is inhaled. Refrigerant must be used and recovered responsibly. Failure to follow this warning may result in personal injury or death.

Figure 10 illustrates the Leak Test procedure, showing gauge set connections to the outdoor unit and HFC-410A/Nitrogen cylinders.

Connect Gauge Set

1. Connect an HFC-410A manifold gauge set high pressure hose to the vapor valve service port.
2. NOTE - Normally, the high pressure hose is connected to the liquid line port. However, connecting it to the vapor port better protects the manifold gauge set from high pressure damage.
3. With both manifold valves closed, connect the cylinder of HFC-410A refrigerant to the center port of the manifold gauge set.
4. NOTE - Later in the procedure, the HFC-410A container will be replaced by the nitrogen container.

Test for Leaks

After the line set has been connected to the indoor and outdoor units, check the line set connections and indoor unit for leaks. Use the following procedure to test for leaks:

1. With both manifold valves closed, connect the cylinder of HFC-410A refrigerant to the center port of the manifold gauge set. Open the valve on the HFC-410A cylinder (vapor only).
2. Open the high pressure side of the manifold to allow HFC-410A into the line set and indoor unit. Weigh in a trace amount of HFC-410A. [A trace amount is a maximum of two ounces (57 g) refrigerant or three pounds (31 kPa) pressure]. Close the valve on the HFC-410A cylinder and the valve on the high pressure side of the manifold gauge set. Disconnect the HFC-410A cylinder.
3. Connect a cylinder of dry nitrogen with a pressure regulating valve to the center port of the manifold gauge set.
4. Adjust dry nitrogen pressure to 150 psig (1034 kPa). Open the valve on the high side of the manifold gauge set in order to pressurize the line set and the indoor unit.
5. After a few minutes, open one of the service valve ports and verify that the refrigerant added to the system earlier is measurable with a leak detector.
6. After leak testing disconnect gauges from service ports.

Evacuating Line Set and Indoor Coil

❗ IMPORTANT: Use a thermocouple or thermistor electronic vacuum gauge that is calibrated in microns. Use an instrument capable of accurately measuring down to 50 microns.

⚠️ WARNING: Possible equipment damage. Avoid deep vacuum operation. Do not use compressors to evacuate a system. Extremely low vacuum can cause internal arcing and compressor failure. Damage caused by deep vacuum operation will void warranty.

Evacuating the system of non-condensables is critical for proper operation of the unit. Non-condensables are defined as any gas that will not condense under temperatures and pressures present during operation of an air conditioning system. Non-condensables and water suction combine with refrigerant to produce substances that corrode copper piping and compressor parts.

Figure 11 illustrates the Evacuating the System procedure, showing gauge set connections to the outdoor unit, vacuum pump, and nitrogen/HFC-410A cylinders.

Connect Gauge Set

NOTE - Remove cores from service valves (if not already done).

1. Connect low side of manifold gauge set with 1/4 SAE in-line tee to vapor line service valve.
2. Connect high side of manifold gauge set to liquid line service valve.
3. Connect micron gauge available connector on the 1/4 SAE in-line tee.
4. Connect the vacuum pump (with vacuum gauge) to the center port of the manifold gauge set. The center port line will be used later for both the HFC-410A and nitrogen containers.

Evacuate the System

1. Open both manifold valves and start the vacuum pump.
2. Evacuate the line set and indoor unit to an absolute pressure of 23,000 microns (29.01 inches of mercury).
3. NOTE - During the early stages of evacuation, it is desirable to close the manifold gauge valve at least once. A rapid rise in pressure indicates a relatively large leak. If this occurs, repeat the leak testing procedure.
4. NOTE - The term absolute pressure means the total actual pressure within a given volume or system, above the absolute zero of pressure. Absolute pressure in a vacuum is equal to atmospheric pressure minus vacuum pressure.
5. When the absolute pressure reaches 23,000 microns (29.01 inches of mercury), perform the following:
   • Close manifold gauge valves
   • Close valve on vacuum pump
   • Turn off vacuum pump
   • Disconnect manifold gauge center port hose from vacuum pump
   • Attach manifold center port hose to a dry nitrogen cylinder with pressure regulator set to 150 psig (1034 kPa) and purge the hose.
   • Open manifold gauge valves to break the vacuum in the line set and indoor unit.
   • Close manifold gauge valves.
6. Shut off the dry nitrogen cylinder and remove the manifold gauge hose from the cylinder. Open the manifold gauge valves to release the dry nitrogen from the line set and indoor unit.
7. Reconnect the manifold gauge to the vacuum pump, turn the pump on, and continue to evacuate the line set and indoor unit until the absolute pressure does not rise above 500 microns (29.9 inches of mercury) within a 20-minute period after shutting off the vacuum pump and closing the manifold gauge valves.
8. When the absolute pressure requirement above has been met, disconnect the manifold hose from the vacuum pump and connect it to an upright cylinder of HFC-410A refrigerant. Open the manifold gauge valve 1 to 2 psig in order to release the vacuum in the line set and indoor unit.
9. Perform the following:
   • Close manifold gauge valves.
   • Shut off HFC-410A cylinder.
   • Reinstall service valve cores by removing manifold hose from service valve. Quickly install cores with core tool while maintaining a positive system pressure.
   • Replace stem caps and secure finger tight, then tighten an additional one-sixth (1/6) of a turn as illustrated.

Electrical

In the U.S.A., wiring must conform with current local codes and the current National Electric Code (NEC). In Canada, wiring must conform with current local codes and the current Canadian Electrical Code (CEC).

Refer to the furnace or air handler installation instructions for additional wiring application diagrams and refer to unit nameplate for minimum circuit ampacity and maximum overcurrent protection size.

24VAC Transformer

Use the transformer provided with the furnace or air handler for low-voltage control power (24VAC - 40 VA minimum).

⚠️ 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.

Size Circuit and Install Service Disconnect Switch

Refer to the unit nameplate for minimum circuit ampacity, and maximum fuse or circuit breaker (HACR per NEC). Install power wiring and properly sized disconnect switch.

Diagram shows a Main Fuse Box/Breaker Panel connected to a Service Disconnect Switch, which is then connected to the outdoor unit.

NOTE - Units are approved for use only with copper conductors. Ground unit at disconnect switch or to an earth ground.

Install Thermostat

Install room thermostat (ordered separately) on an inside wall approximately in the center of the conditioned area and 5 feet (1.5m) from the floor. It should not be installed on an outside wall or where it can be affected by sunlight or drafts.

Diagram shows a thermostat mounted on an interior wall, 5 feet from the floor.

NOTE - 24VAC, Class II circuit connections are made in the control panel.

Typical Field Wiring

Figure 12 illustrates Typical Field Wiring for a Heat Pump Application with CBA38MV, showing connections between the Heat Pump Unit, outdoor sensor, ComfortSense 7500 Thermostat, and Air Handler Control. It includes notes on required components like the X2658 Outdoor Sensor and 47W97 Resistor Kit, and important instructions regarding cutting control links.

Figure 13 illustrates Heat Pump Application - Humiditrol® and Second-Stage Outdoor Fan Relay Wiring with CBA38MV, showing similar connections with emphasis on Humiditrol® and second-stage fan relay.

System Operation

Unit Components

❗ IMPORTANT: Some scroll compressors have an internal vacuum protector that will unload scrolls when suction pressure goes below 20 psig. A hissing sound will be heard when the compressor is running unloaded. Protector will reset when low pressure in system rises above 40 psig. DO NOT REPLACE COMPRESSOR.

The outdoor unit and indoor blower cycle on demand from the room thermostat. If the thermostat blower switch is in the ON position, the indoor blower operates continuously.

Bi-Flow Liquid Line Filter Drier

The unit is equipped with a large-capacity bi-flow filter drier which keeps the system clean and dry. If replacement is necessary, order another of the same design and capacity. The replacement filter drier must be suitable for use with HFC-410A refrigerant.

Low Pressure Switch (S87)

The ML16XP1 is equipped with an auto-reset low pressure switch which is located on the vapor line. The switch shuts off the compressor when the vapor pressure falls below the factory setting. This switch, which is ignored during defrost operation, closes at pressures at or above 40 + 5 psig (276 + 34 kPa) and opens at 25 + 5 psig (172 + 34 kPa). It is not adjustable.

Low Pressure Switch Bypass (S41) (Optional)

• For use in applications where the heat pump is operated in outdoor ambient temperatures below 15°F.
• Prevents nuisance trips from the low pressure switch.
• Wired in parallel with the low pressure switch.

High Pressure Switch (S4)

The ML16XP1 is equipped with an auto-reset high pressure switch (single-pole, single-throw) which is located on the liquid line. The switch shuts off the compressor when discharge pressure rises above the factory setting. The switch is normally closed and is permanently adjusted to trip (open) at 590 + 15 psig (4068 + 103 kPa).

NOTE – A Schrader core is under the pressure switches.

Crankcase Heater (HR1) and Thermostat Switch (S40)

Certain units are equipped with a belly band type crankcase heater. HR1 prevents liquid from accumulating in the compressor. The HR1 is controlled by a single pole, single throw thermostat switch (S40) located on the liquid line. On all units, the heater is on when there is no compressor operation.

Thermal Protection Switch (S173) – Compressor Mounted

Some ML16XP1 units are equipped with a compressor mounted normally closed temperature switch that prevents compressor damage due to overheating caused by internal friction. The switch is located on top of the compressor casing (see figure 1). This switch senses the compressor casing temperature and opens at 239-257°F (115°C-125°C) to shut off compressor operation. The auto-reset switch closes when the compressor casing temperature falls to 151-187°F (66°C-86°C), and the compressor is re-energized. This single-pole, single-throw (SPST) bi-metallic switch is wired in series with the 24V Y input signal to control compressor operation.

System Configuration

Demand Defrost Control (A108)

The demand defrost control measures differential temperatures to detect when the system is performing poorly because of ice build-up on the outdoor coil. The control self-calibrates when the defrost system starts and after each system defrost cycle. The demand defrost control components are shown in figure 14.

• Demand defrost control connections, jumpers and LED locations are shown in figure 14.
• Demand defrost control connections, jumpers and LED descriptions are listed on table 3.
• Demand defrost control status, fault and lockout LEDs are listed in table 4.

Demand Defrost Control (A108) Diagram

Figure 14 shows the Demand Defrost Control board (A108), labeling TEST PINS (P1), DEFROST TERMINATION PIN SETTINGS (P1), SENSOR CONNECTION (COIL AND AMBIENT SENSORS) (P4), DELAY PINS (P5), REVERSING VALVE (O OUT), PRESSURE SWITCH CIRCUIT CONNECTIONS, LOW AMBIENT THERMOSTAT PINS (P3), DIAGNOSTIC LEDS (DS1 AND DS2), and 24V TERMINAL STRIP CONNECTIONS (P2).

Note - Component locations vary by board manufacturer.

Demand Defrost Control (A108) Inputs, Outputs and Configurable Settings

Defrost System

This section addresses:

• Emergency Heat
• Defrost System Overview
• Defrost Control Connections, Jumper Settings and Features
• Operational Mode Overview (Calibration, Normal and Defrost)
• Defrost Cycle Actuation

Emergency Heat (Amber Light)

An emergency heat function is designed into some room thermostats. This feature is applicable when isolation of the outdoor unit is required, or when auxiliary electric heat is staged by outdoor thermostats. When the room thermostat is placed in the emergency heat position, the outdoor unit control circuit is isolated from power and field-provided relays bypass the outdoor thermostats. An amber indicating light simultaneously comes on to remind the homeowner that he is operating in the emergency heat mode.

Emergency heat is usually used during an outdoor unit shutdown, but it should also be used following a power outage if power has been off for over an hour and the outdoor temperature is below 50°F (10°C). System should be left in the emergency heat mode at least six hours to allow the crankcase heater sufficient time to prevent compressor slugging.

Defrost System Overview

The control monitors ambient temperature, outdoor coil temperature, and total run time to determine when a defrost cycle is required. The coil temperature probe is designed with a spring clip to allow mounting to the outside coil tubing. The location of the coil sensor is important for proper defrost operation.

NOTE – The demand defrost control accurately measures the performance of the system as frost accumulates on the outdoor coil. This typically will translate into longer running time between defrost cycles as more frost accumulates on the outdoor coil before the demand defrost control initiates defrost cycles.

Defrost Control Connections, Jumpers Settings and Features

Defrost Temperature Termination Jumper Settings (P1)

The demand defrost control selections are: 50, 70, 90 and 100°F (10, 21, 32 and 38°C). The shunt termination pin is factory set at 50°F (10°C). If temperature shunt is not installed, default termination temperature is 90°F (32°C).

Test Pins (P1) Function

Placing the jumper on the field test pins (P1) allows the technician to:

• Clear short cycle lockout
• Clear five-strike fault lockout
• Cycle the unit in and out of defrost mode
• Place the unit in defrost mode to clear the coil

Compressor Delay Mode (P5)

The demand defrost control has a field-selectable function to reduce occasional sounds that may occur while the unit is cycling in and out of the defrost mode. When a jumper is installed on the DELAY pins, the compressor will be cycled off for 30 seconds going in and out of the defrost mode. Units are shipped with jumper installed on DELAY pins.

NOTE - The 30 second off cycle is NOT functional when jumpering the TEST pins.

Diagnostic LEDs and Checklist

Demand Defrost Control (A108) Diagnostic LEDs

The state (Off, On, Flashing) of two LEDs on the demand defrost control (DS1 [Red] and DS2 [Green]) indicate diagnostics conditions that are described in table 4.

(Each fault adds 1 strike to that code's counter; 5 strikes per code = LOCKOUT)

Field Operation Checklist for Two-Stage Modulation Compressors

Maintenance

❗ IMPORTANT: After testing has been completed, properly reposition test jumper across desired timing pins.

Dealer Maintenance

⚠️ 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.

⚠️ 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.

NOTICE! Failure to follow instructions will cause damage to the unit.

This unit is equipped with an aluminum coil. Aluminum coils may be damaged by exposure to solutions with a pH below 5 or above 9. The aluminum coil should be cleaned using potable water at a moderate pressure (less than 50psi). If the coil cannot be cleaned using water alone, Lennox recommends use of a coil cleaner with a pH in the range of 5 to 9. The coil must be rinsed thoroughly after cleaning.

In coastal areas, the coil should be cleaned with potable water several times per year to avoid corrosive buildup (salt).

Maintenance and service must be performed by a qualified installer or service agency. At the beginning of each cooling season, the system should be checked as follows:

Outdoor Unit

1. Clean and inspect outdoor coil (may be flushed with a water hose). Ensure power is off before cleaning.
2. Outdoor unit fan motor is pre-lubricated and sealed. No further lubrication is needed.
3. Visually inspect all connecting lines, joints and coils for evidence of oil leaks.
4. Check all wiring for loose connections.
5. Check for correct voltage at unit (unit operating).
6. Check amp draw on outdoor fan motor.
7. Inspect drain holes in coil compartment base and clean if necessary.

NOTE – If insufficient heating or cooling occurs, the unit should be gauged and refrigerant charge should be checked.

Outdoor Coil

It may be necessary to flush the outdoor coil more frequently if it is exposed to substances which are corrosive or which block airflow across the coil (e.g., pet urine, cottonwood seeds, fertilizers, fluids that may contain high levels of corrosive chemicals such as salts)

• Outdoor Coil – The outdoor coil may be flushed with a water hose.
• Outdoor Coil (Sea Coast) – Moist air in ocean locations can carry salt, which is corrosive to most metal. Units that are located near the ocean require frequent inspections and maintenance. These inspections will determine the necessary need to wash the unit including the outdoor coil. Consult your installing contractor for proper intervals/procedures for your geographic area or service contract.

Indoor Unit

1. Clean or change filters.
2. Lennox blower motors are prelubricated and permanently sealed. No more lubrication is needed.
3. Adjust blower speed for cooling. Measure the pressure drop over the coil to determine the correct blower CFM. Refer to the unit information service manual for pressure drop tables and procedure.
4. Belt Drive Blowers - Check belt for wear and proper tension.
5. Check all wiring for loose connections.
6. Check for correct voltage at unit. (blower operating)
7. Check amp draw on blower motor.

Indoor Coil

1. Clean coil if necessary.
2. Check connecting lines, joints and coil for evidence of oil leaks.
3. Check condensate line and clean if necessary.

Homeowner Maintenance

Cleaning of the outdoor unit's coil should be performed by a trained service technician. Contact your dealer and set up a schedule (preferably twice a year, but at least once a year) to inspect and service your outdoor unit. The following maintenance may be performed by the homeowner.

Routine Maintenance and Operation

❗ IMPORTANT: Sprinklers and soaker hoses should not be installed where they could cause prolonged exposure to the outdoor unit by treated water. Prolonged exposure of the unit to treated water (i.e., sprinkler systems, soakers, waste water, etc.) will corrode the surface of the steel and aluminum parts, diminish performance and affect longevity of the unit.

Outdoor Coil

The outdoor unit must be properly maintained to ensure its proper operation.

• Please contact your dealer to schedule proper inspection and maintenance for your equipment.
• Make sure no obstructions restrict airflow to the outdoor unit.
• Grass clippings, leaves, or shrubs crowding the unit can cause the unit to work harder and use more energy.
• Keep shrubbery trimmed away from the unit and periodically check for debris which collects around the unit.

Routine Maintenance

In order to ensure peak performance, your system must be properly maintained. Clogged filters and blocked airflow prevent your unit from operating at its most efficient level.

1. Air Filter – Ask your Lennox dealer to show you where your indoor unit's filter is located. It will be either at the indoor unit (installed internal or external to the cabinet) or behind a return air grille in the wall or ceiling. Check the filter monthly and clean or replace it as needed.
2. Disposable Filter – Disposable filters should be replaced with a filter of the same type and size. NOTE – If you are unsure about the filter required for your system, call your Lennox dealer for assistance.
3. Reusable Filter – Many indoor units are equipped with reusable foam filters. Clean foam filters with a mild soap and water solution; rinse thoroughly; allow filter to dry completely before returning it to the unit or grille. NOTE – The filter and all access panels must be in place any time the unit is in operation.
4. Electronic Air Cleaner – Some systems are equipped with an electronic air cleaner, designed to remove airborne particles from the air passing through the cleaner. If your system is so equipped, ask your dealer for maintenance instructions.
5. Indoor Unit – The indoor unit's evaporator coil is equipped with a drain pan to collect condensate formed as your system removes humidity from the inside air. Have your dealer show you the location of the drain line and how to check for obstructions. (This would also apply to an auxiliary drain, if installed.)

Thermostat Operation

See the thermostat homeowner manual for instructions on how to operate your thermostat.

Heat Pump Operation

Your new Lennox heat pump has several characteristics that you should be aware of:

• Heat pumps satisfy heating demand by delivering large amounts of warm air into the living space. This is quite different from gas- or oil-fired furnaces or an electric furnace which deliver lower volumes of considerably hotter air to heat the space.
• Do not be alarmed if you notice frost on the outdoor coil in the winter months. Frost develops on the outdoor coil during the heating cycle when temperatures are below 45°F (7°C). An electronic control activates a defrost cycle lasting 5 to 15 minutes at preset intervals to clear the outdoor coil of the frost.
• During the defrost cycle, you may notice steam rising from the outdoor unit. This is a normal occurrence. The thermostat may engage auxiliary heat during the defrost cycle to satisfy a heating demand; however, the unit will return to normal operation at the conclusion of the defrost cycle.

Extended Power Outage

The heat pump is equipped with a compressor crankcase heater which protects the compressor from refrigerant slugging during cold weather operation.

If power to your unit has been interrupted for several hours or more, set the room thermostat selector to the EMERGENCY HEAT setting to obtain temporary heat without the risk of serious damage to the heat pump.

In EMERGENCY HEAT mode, all heating demand is satisfied by auxiliary heat; heat pump operation is locked out. After a six-hour compressor crankcase warm-up period, the thermostat can be switched to the HEAT setting and normal heat pump operation may resume.

Preservice Check

If your system fails to operate, check the following before calling for service:

• Verify room thermostat settings are correct.
• Verify that all electrical disconnect switches are ON.
• Check for any blown fuses or tripped circuit breakers.
• Verify unit access panels are in place.
• Verify air filter is clean.
• If service is needed, locate and write down the unit model number and have it handy before calling.

Accessories

For update-to-date information, see any of the following publications:

• Lennox ML16XP1 Product Specification bulletin
• Lennox Product Catalog
• Lennox Price Book

Wiring and Sequence of Operation

Figure 15 shows Typical Unit Wiring for units -018 thru -030.

Figure 16 shows Typical Unit Wiring for units -036 thru -060.

Figure 17 shows Typical Factory Wiring for units -018 thru -030.

Figure 18 shows Typical Factory Wiring for units -036 thru -060.

ML16XP1 Operating Sequence

This is the sequence of operation for ML16XP1 series units. The sequence is outlined by numbered steps which correspond to circled numbers on the adjacent diagram. The steps are identical for both cooling and first stage heating demand with the exception reversing valve L1 is energized during cooling demand and de-energized during heating demand.

NOTE – Transformer in indoor unit supplies power (24 VAC) to the thermostat and outdoor unit controls.

COOLING:

Internal thermostat wiring energizes terminal O by cooling mode selection, energizing the reversing valve L1.

1. Demand initiates at Y1 in the thermostat.
2. 24VAC energizes compressor contactor K1.
3. K1-1 N.O. closes, energizing compressor (B1) and outdoor fan motor (B4).

END OF COOLING DEMAND:

1. Demand is satisfied. Terminal Y1 is de-energized.
2. Compressor contactor K1 is de-energized.
3. K1-1 opens and compressor (B1) and outdoor fan motor (B4) are de-energized and stop immediately.

FIRST STAGE HEAT:

Internal thermostat wiring de-energizes terminal O by heating mode selection, de-energizing the reversing valve L1.

See steps 1, 2 and 3.

End of FIRST STAGE HEAT:

See steps 4, 5 and 6.

DEFROST MODE:

When a defrost cycle is initiated, the control energizes the reversing valve solenoid and turns off the condenser fan. The control will also put 24VAC on the “W1” (auxiliary heat) line. The unit will stay in this mode until either the coil sensor temperature is above the selected termination temperature, the defrost time of 14 minutes has been completed, or the room thermostat demand cycle has been satisfied. (If the temperature select shunt is not installed, the default termination temperature will be 90°F.) If the room thermostat demand cycle terminates the cycle, the defrost cycle will be held until the next room thermostat demand cycle. If the coil sensor temperature is still below the selected termination temperature, the control will continue the defrost cycle until the cycle is terminated in one of the methods mentioned above. If a defrost is terminated by time and the coil temperature did not remain above 35°F (2°C) for 4 minutes the control will go to the 30-minute Time/Temperature mode.

Servicing Units Void of Charge

If the outdoor unit is void of refrigerant, clean the system using the procedure described below.

1. Leak check system using procedure outlined on page 17.
2. Evacuate the system using procedure outlined on page 18.
3. Use nitrogen to break the vacuum and install a new filter drier in the system.
4. Evacuate the system again using procedure outlined on page 18.
5. Weigh in refrigerant.

Start-Up

❗ IMPORTANT: If unit is equipped with a crankcase heater, it should be energized 24 hours before unit start-up to prevent compressor damage as a result of slugging.

1. Rotate fan to check for binding.
2. Inspect all factory and field-installed wiring for loose connections.
3. After evacuation is complete, open the liquid line and suction line service valves to release the refrigerant charge (contained in outdoor unit) into the system.
4. Replace the stem caps and tighten as specified in Operating Service Valves on page 7.
5. Check voltage supply at the disconnect switch. The voltage must be within the range listed on the unit's nameplate. If not, do not start the equipment until you have consulted with the power company and the voltage condition has been corrected.
6. Set the thermostat for a cooling demand. Turn on power to the indoor unit and close the outdoor unit disconnect switch to start the unit.
7. Recheck voltage while the unit is running. Power must be within range shown on the nameplate.
8. Check system for sufficient refrigerant by using the procedures listed under Start-Up and Charging Procedures.
9. Recheck voltage while the unit is running. Power must be within range shown on the nameplate.

Start-Up and Performance Checklist

This section provides a checklist for start-up and performance verification.

Job Name: _________________________ Job no.: ____________ Date: ____________

Job Location: _________________________ City: ____________ State: ________

Installer: _________________________ City: ____________ State: ________

Unit Model No.: _________________________ Serial No.: _________________________ Service Technician: _________________________

Nameplate Voltage: _______________ Rated Load Ampacity: _______________ Compressor: _______________ Outdoor Fan: _______________

Maximum Fuse or Circuit Breaker: _______________

Electrical Connections Tight? ☐ Indoor Filter clean? ☐ Supply Voltage (Unit Off): _______________

Indoor Blower RPM: _______________ S.P. Drop Over Indoor (Dry): _______________ Outdoor Coil Entering Air Temp.: _______________

Discharge Pressure: _______________ Vapor Pressure: _______________ Refrigerant Charge Checked? ☐

Refrigerant Lines:
Leak Checked? ☐ Properly Insulated? ☐ Outdoor Fan Checked? ☐

Service Valves:
Fully Opened? ☐ Caps Tight? ☐

Thermostat
Voltage With Compressor Operating: _______________ Calibrated? ☐ Properly Set? ☐ Level? ☐