Lennox T-Class TSA*S4 Units Installation Instructions

Table of Contents

• Shipping and Packing List
• Outdoor Unit
• Unit Dimensions
• Typical Unit Parts Arrangement
• Model Number Identification
• General Information
• Operating Gauge Set and Service Valves
• Recovering Refrigerant from Existing System
• New Outdoor Unit Placement
• New or Replacement Line Set
• Brazing Connections
• Flushing Line Set and Indoor Coil
• Installing Indoor Metering Device
• Leak Test Line Set and Indoor Coil
• Evacuating Line Set and Indoor Coil
• Electrical Connections
• Servicing Unit Delivered Void of Charge
• Unit Start-Up
• System Refrigerant
• System Operation
• Maintenance
• Start-Up and Performance Checklist

Shipping and Packing List

Check the unit for shipping damage and listed items below are intact. If damaged, or if parts are missing, immediately contact the last shipping carrier.

• 1 Assembled outdoor unit
• 1 Liquid line filter drier

Outdoor Unit

This outdoor unit is designed for use with HFC-410A refrigerant only. This unit must be installed with an approved indoor air handler or coil. See the Lennox TSA*S4 Engineering Handbook for approved indoor component matchups.

This outdoor unit is designed for use in thermal expansion valve (TXV) systems only.

Unit Dimensions

The unit dimensions are provided in inches (mm) for the A and B sides, as shown in the side view diagrams. The diagrams illustrate the outdoor coil fan, compressor, and suction/liquid line connections.

Typical Unit Parts Arrangement

The typical unit parts arrangement diagram shows the location of key components within the outdoor unit, including the dual run capacitor (C12) for T-Voltage, single run capacitor (C12) for M-Voltage, ground lug, contactor (K1), cutout for high voltage conduit, high pressure switch (S4), and crankcase heater thermostat (S40).

Model Number Identification

The model number follows a specific format to identify unit characteristics:

• Brand/Family: T = T-Class Product Line
• Unit Type: S = Split-System Air Conditioner
• Major Design Sequence: A = 1st Generation, B = 2nd Generation
• Model Size: 024 = 2 Tons, 030 = 2.5 Tons, 036 = 3 Tons, 048 = 4 Tons, 060 = 5 Tons
• Cooling Efficiency: S = Standard Efficiency
• Voltage: M = 380/420V-3 phase 50Hz, T = 220/240V-1 phase 50Hz
• Minor Design Sequence: 1 = 1st Revision, 2 = 2nd Revision, 3 = 3rd Revision
• Coil Type: 4 = Four-sided
• Part Load Capability: N = No part load, single stage compressor
• Refrigerant Type: 4 = R-410A

General Information

These instructions are intended as a general guide and do not supersede local codes in any way. Consult authorities who have jurisdiction before installation.

Operating Gauge Set and Service Valves

These instructions are intended as a general guide and do not supersede local codes in any way. Consult authorities who have jurisdiction before installation.

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 minimum). Fully insert the wrench into the valve stem recess. Service valve stems are factory-torqued (9-25 ft-lbs) to prevent refrigerant loss. Using a wrench rated less than 50Rc risks rounding or breaking the wrench, or stripping the valve stem recess. Refer to Lennox Service and Application Notes #C-08-1 for details.

IMPORTANT To prevent stripping caps, use the appropriately sized wrench and fit it snugly over the cap before tightening.

USING MANIFOLD GAUGE SET When checking the system charge, use a manifold gauge set that features low loss anti-blow back fittings.

Operating Service Valves

The liquid and vapor line service valves are used for refrigerant handling, flushing, leak testing, evacuation, charging, and checking. Each valve has a service port with a factory-installed valve stem.

Angle Type Service Valve:

1. Remove the stem cap with an appropriately sized wrench.
2. Use a service wrench with a hex-head extension (3/16" for liquid, 5/16" for vapor) to back the stem out counterclockwise until fully open.

The diagram shows the valve stem in both the open (back-seated) and closed (front-seated) positions. When the valve is OPEN, the service port is open to the line set, indoor, and outdoor unit. When CLOSED, the service port is open to the line set and indoor unit.

Ball Type Service Valve:

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

The diagram illustrates the operation of the ball valve.

To Access Service Port:

1. Remove the service port cap.
2. Connect the gauge set to the service port.
3. When testing is complete, replace the service port cap and tighten finger-tight, then use a wrench for an additional 1/6 turn clockwise (or torque to Table 1).

Reinstall Stem Cap:

1. Replace the stem cap and tighten finger-tight.
2. Use a torque wrench to the value in Table 1, or tighten finger-tight and use a wrench for an additional 1/12 turn clockwise.

Recovering Refrigerant from Existing System

RECOVERING REFRIGERANT FROM SYSTEM

1. DISCONNECT POWER: Disconnect all power to the existing outdoor unit at the service disconnect switch or main fuse box/breaker panel.
2. CONNECT MANIFOLD GAUGE SET: Connect a gauge set, clean recovery cylinder, and recovery machine to the service ports of the existing unit, following the recovery machine's instructions.
3. RECOVERING REFRIGERANT: Remove existing refrigerant using one of the following methods:
   • METHOD 1: For units without shut-off valves or if the unit is not operational. Remove all refrigerant and check gauges to confirm the system is void.
   • METHOD 2: For units with manual shut-off valves. Follow specific steps to recover refrigerant, noting that certain system conditions (high/low pressure switches, internal pressure relief valve, compressor vacuum protection) may prevent full recovery. If the compressor cannot pump down to a lower pressure, shut off the vapor valve, turn off main power, and use a recovery machine for remaining refrigerant.

The procedure involves starting the system in cooling mode, closing the liquid line valve, using the compressor to pump refrigerant, turning off power, and using a recovery machine. It also notes potential bypass of low-pressure switches and checking for backflow.

Installation Clearances

Proper clearances are essential for unit operation and serviceability. The diagrams illustrate required clearances:

• Clearance on All Sides: Minimum clearances are 6 inches (152 mm) on one side, 12 inches (305 mm) on another, and 30 inches (762 mm) on the third side. One side must have 36 inches (914 mm) clearance.
• Clearance Above Unit: A minimum of 48 inches (1219 mm) is required above the unit.
• Clearance Between Two Units: A minimum of 24 inches (610 mm) is required between units.

NOTES: Clearance to one of the other three sides must be 36 inches (914mm). Clearance to one of the remaining two sides may be 12 inches (305mm) and the final side may be 6 inches (152mm).

Placement, and Slab Mounting

New Outdoor Unit Placement:

Consider the following when positioning the unit:

• Sound Ordinances: Install the unit as far as possible from property lines to comply with local sound ordinances.
• Window Placement: Avoid installing the unit directly outside a window, as glass transmits sound effectively. The illustration shows proper placement relative to a window.

Slab Mounting:

The unit should be placed on an elevated surface or slab. If installing at grade level, the slab top should be high enough to prevent water collection. The slab may be level or have a slope tolerance away from the building of not more than two degrees (or 2 inches per 5 feet / 50 mm per 1.5 m).

For roof installations, ensure the unit is at least 4 inches (102 mm) above the roof surface and that weight is properly distributed over joists and rafters. Redwood or steel supports are recommended.

CAUTION Take proper precaution when lifting heavy objects to avoid injury.

Refrigerant Line Set

This section covers new installations or replacements of existing line sets. If a line set is not required, proceed to Brazing Connections.

Line Set Isolation: Seal and isolate openings where refrigerant lines pass through walls to prevent vibration transmission to the building structure. Proper isolation minimizes vibration and noise.

High-Efficiency Air Conditioner Considerations:

Field refrigerant piping consists of liquid and suction lines. Lennox L15 (braze, non-flare) series line sets or field-fabricated lines are used. For lines longer than 50 feet, contact Lennox Technical Support for assistance, providing unit model, size, line set diameters, total length, and elbow count.

IMPORTANT Mineral oils are not compatible with HFC-410A. Polyol ester (POE) oil must be used. The compressor is charged with POE oil for line sets up to 50 feet. For systems over 20 pounds, add one ounce of POE oil for every five pounds of refrigerant. Recommended POE oils include Mobil EAL ARCTIC 22 CC or ICI EMKARATE RL32CF.

Matching with New or Existing Indoor Coil and Line Set: If using an existing indoor coil with a liquid line that served as a metering device (RFC), the liquid line must be replaced prior to installing the TSA*S4 unit. Typically, RFC lines are 1/4" copper.

Liquid Line Filter Drier Installation: The provided filter drier must be installed in the liquid line between the outdoor unit's liquid line service valve and the indoor coil's metering device. This ensures a clean, moisture-free system and is required to maintain warranty. See Brazing Connections for installation procedures.

The diagram shows the filter drier installed in the liquid line between the outdoor unit service valve and the indoor coil.

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

Refrigerant Line Set Isolation: The illustrations show examples of proper line set isolation for vertical and horizontal runs, using wire ties, hangers, and sleeves to prevent contact with structures and minimize vibration.

Brazing Connections

Use the procedures outlined in figures 8 and 9 for brazing line set connections to service valves.

IMPORTANT If the unit is matched with a coil previously charged with mineral oil, or manufactured before January 1999, the coil and line set must be flushed. Residual mineral oil can act as an insulator, clog the expansion device, and reduce performance. Failure to flush voids the warranty.

IMPORTANT Polyol ester (POE) oils absorb moisture quickly. Keep the refrigerant system closed as much as possible. Do not remove line set or service valve caps until ready to make connections.

WARNING Bleeding refrigerant from the high side may pressurize the low side. Applying a brazing torch to a pressurized system can ignite the refrigerant/oil mixture. Check high and low pressures before applying heat.

WARNING When using high-pressure gas like dry nitrogen for pressurization, use a regulator that controls pressure down to 1 or 2 psig (6.9 to 13.8 kPa).

CAUTION Brazing alloys and flux are hazardous. Avoid breathing fumes, work in ventilated areas, wear gloves and eye protection, and wash hands after handling.

IMPORTANT Connect the gauge set low-pressure side to the vapor line service valve. Repeat for brazing the liquid line to the service port valve.

IMPORTANT Allow braze joints to cool before removing wet rags. Temperatures above 250°F can damage valve seals.

IMPORTANT Use silver alloy brazing rods: 5% minimum silver for copper-to-copper, 45% minimum for copper-to-brass/steel.

WARNING Fire, Explosion, and Personal Safety Hazard. Never use oxygen to pressurize or purge refrigeration lines, as it can cause fire/explosion.

Brazing Procedures (Figure 8 & 9):

1. Cut and Debur: Cut refrigerant line ends square and debur them. Ensure the pipe remains round and is not crimped.
2. Cap and Core Removal: Remove service caps and cores from vapor and liquid line service ports. Diagrams show the correct procedure and highlight not to crimp the connector when the pipe is smaller than the connection.
3. Attach Manifold Gauge Set: Connect the gauge set for brazing. Flow regulated nitrogen (1-2 psig) through the low-side gauge set into the liquid line service port and out the suction/vapor line service port. Diagrams show connections for nitrogen and gauge set.
4. Wrap Service Valves: Wrap service valve bodies and copper tube stubs with saturated cloths to protect seals and paint during brazing.
5. Flow Nitrogen: Continue flowing nitrogen (1-2 psig) through the valve stem port.
6. Braze Line Set: Braze the line set to the service valves, ensuring saturated cloths are in place. Point the flame away from the service valve.
7. Cooling: Allow braze joints to cool, applying additional wet cloths. Do not remove rags until piping is cool.
8. Preparation for Next Step: After brazing, disconnect the gauge set. Apply wet rags to cool piping. Remove wet cloths once cool. Refer to unit installation instructions for the next step.

Flushing Line Set and Indoor Coil

Flushing is required if the existing indoor coil and line set are used. Otherwise, proceed to Installing Indoor Metering Device.

Typical Existing Fixed Orifice Removal Procedure (Uncased Coil): Steps involve removing access panels, shipping clamps, disconnecting the liquid line, removing the fixed orifice, and temporarily reconnecting the liquid line.

Typical Existing Expansion Valve Removal Procedure (Uncased Coil): Steps involve removing access panels, shipping clamps, disconnecting the equalizer line, vapor line sensing bulb, liquid line, and the check expansion valve. The diagram illustrates these components.

Connect Gauges and Equipment for Flushing Procedure: The diagram shows the setup using an inverted cylinder of clean refrigerant, a gauge manifold, and a recovery machine.

Flushing Line Set: The line set and indoor coil must be flushed with the same amount of clean refrigerant as the original charge. Procedures involve using a recovery machine for liquid and vapor refrigerant recovery, inverting the refrigerant cylinder, and ensuring the system is evacuated.

Installing Indoor Metering Device

This unit is designed for systems using a fixed orifice (included) or an expansion valve (purchased separately) at the indoor coil. Refer to the Lennox TSA*S4 Engineering Handbook for approved expansion valve kits.

Indoor Expansion Valve Installation:

1. Remove the field-provided fitting used for temporary reconnection.
2. Install Teflon® rings around the expansion valve stubbed end and lubricate threads.
3. Attach the expansion valve stub to the liquid line orifice housing, finger tighten, and then tighten an additional 1/2 turn clockwise (or 20 ft-lb).
4. Place the remaining Teflon® washer on the other end of the expansion valve and lubricate.
5. Attach the liquid line assembly to the expansion valve, finger tighten, and then tighten an additional 1/2 turn clockwise (or 20 ft-lb).

Sensing Bulb Installation: Attach the vapor line sensing bulb in the correct orientation using the clamp and screws. Ensure proper thermal contact before insulating.

Equalizer Line Installation: Remove existing fittings from the equalizer line port on the vapor line. Connect the equalizer line from the expansion valve to the vapor line equalizer port, finger tighten the flare nut plus 1/8 turn (7 ft-lbs).

Diagrams illustrate the installation of the expansion valve, sensing bulb, and equalizer line, including positioning guidelines for the sensing bulb based on line size.

Leak Test Line Set and Indoor Coil

IMPORTANT Leak detectors must be capable of sensing HFC refrigerant.

After leak testing, proceed to Evacuating Line Set and Indoor Coil.

WARNING When using high-pressure gas like dry nitrogen, use a regulator that controls pressure down to 1 or 2 psig (6.9 to 13.8 kPa).

WARNING Refrigerant can be harmful if inhaled. Use and recover responsibly. Failure to follow warnings may result in personal injury or death.

Procedure:

1. Connect Gauge Set: Connect an HFC-410A manifold gauge set. The high-pressure hose connects to the vapor valve service port for better protection. Connect the HFC-410A cylinder to the center port.
2. Test for Leaks: After connecting the line set and indoor unit, test for leaks. Introduce a trace amount of HFC-410A (max 2 oz or 3 psi). Disconnect the HFC-410A cylinder. Connect a dry nitrogen cylinder with a regulator to the center port and pressurize the line set and indoor unit to 150 psig (1034 kPa). Open a service valve port to check for refrigerant with a leak detector. Disconnect gauges after testing.

Evacuating Line Set and Indoor Coil

CONNECT GAUGE SET: Remove service valve cores if not already done. Connect the low side of the manifold gauge set to the vapor line service valve via a tee, the high side to the liquid line service valve, and the micron gauge to the tee. Connect the vacuum pump to the center port of the manifold gauge set.

EVACUATE THE SYSTEM:

1. Open manifold valves and start the vacuum pump.
2. Evacuate the system to an absolute pressure of 23,000 microns (29.01 inches of mercury). A rapid pressure rise indicates a leak.
3. When 23,000 microns is reached, close manifold gauge valves, close the vacuum pump valve, and turn off the pump.
4. Disconnect the vacuum pump hose from the center port. Attach a dry nitrogen cylinder with a regulator (150 psig) and purge the hose. Open manifold gauge valves to break the vacuum.
5. Close manifold gauge valves. Shut off the nitrogen cylinder and remove the hose. Open manifold gauge valves to release nitrogen.
6. Reconnect the manifold gauge to the vacuum pump and continue evacuating until the absolute pressure does not rise above 500 microns within 20 minutes after shutting off the pump and closing valves.
7. Once the 500-micron requirement is met, disconnect the vacuum pump hose and connect it to an HFC-410A refrigerant cylinder. Open the manifold gauge valve 1-2 psig to release vacuum.
8. Close manifold gauge valves, shut off the HFC-410A cylinder. Reinstall service valve cores using a core tool while maintaining system pressure. Replace stem caps, tighten finger-tight, then an additional 1/6 turn.

Electrical Connections

Wiring must conform to current local codes and the National Electric Code (NEC) in the U.S.A., or the Canadian Electrical Code (CEC) in Canada. Refer to furnace or air handler installation instructions for diagrams and specifications.

SIZE CIRCUIT AND INSTALL DISCONNECT SWITCH: Refer to the unit nameplate for minimum circuit ampacity and maximum fuse/breaker size. Install power wiring and a properly sized disconnect switch.

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

INSTALL THERMOSTAT: Install the thermostat (ordered separately) on an inside wall, centered in the conditioned area, about 5 feet (1.5m) from the floor. Avoid outside walls or areas affected by sunlight or drafts.

WARNING Electric Shock Hazard. Unit must be grounded per national and local codes. Line voltage is present at all components when the unit is not operating. Disconnect all remote electric power supplies before opening access panels.

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

Routing High Voltage/ Ground and Control Wiring

HIGH VOLTAGE / GROUND WIRES: Trim and secure excess high voltage wiring away from low voltage wiring. Use the control panel cutout and a conduit fitting for conduit installation.

CONTROL WIRING: Install low voltage wiring from outdoor to indoor unit and from thermostat to indoor unit.

1. Run 24VAC control wires through a hole with a grommet and secure with a wire tie.
2. Make 24VAC thermostat wire connections. Connect yellow wire to Y1 and black wire to C (common) from the contactor.

NOTE: Select thermostat wire gauge based on voltage and wire run length (refer to table). Do not bundle excess 24VAC control wires inside the control panel.

The diagram illustrates typical low voltage field wiring for thermostat, indoor unit, and outdoor unit connections (R, W1, Y, G, C). It also shows high voltage wiring for three-phase and single-phase connections.

NOTE: Wire ties provide strain relief for low voltage control wires and maintain separation between low and high voltage circuits.

Typical Field Wiring Diagrams

Diagrams are provided for M Voltage (380/420v, 3PH, 50Hz) and T Voltage (220/240v, 1PH, 50Hz) showing the typical field wiring connections for outdoor fans, compressors, contactors, capacitors, switches, and control circuits. Key components are listed with descriptions.

WARNING Electric Shock Hazard. Unit must be grounded in accordance with national and local codes.

NOTE If any wire is replaced, use wire of the same size, rating, insulation thickness, and termination.

Servicing Units Delivered Void of Charge

If the outdoor unit is void of refrigerant, follow these steps:

1. Leak check the system.
2. Evacuate the system.
3. Use nitrogen to break the vacuum and install a new filter drier.
4. Evacuate the system again.
5. Weigh in refrigerant as per Figure 20.

Unit Start-Up

IMPORTANT If the unit has a crankcase heater, energize it 24 hours before start-up to prevent compressor damage from slugging.

1. Check that the fan rotates freely.
2. Inspect all factory and field-installed wiring for loose connections.
3. After evacuation, open the liquid and suction line service valves to release refrigerant into the system.
4. Replace stem caps as specified in Operating Service Valves.
5. Check voltage supply at the disconnect switch. Ensure it is within the range listed on the unit's nameplate. Do not start if voltage is incorrect.
6. Set the thermostat for cooling demand. Turn on power to the indoor unit and close the outdoor unit disconnect switch.
7. Recheck voltage while the unit is running.
8. Check system for sufficient refrigerant using Start-Up and Charging Procedures.

System Refrigerant: This section covers connecting gauge sets, checking/adjusting indoor airflow, and adding/removing refrigerant.

Gauge Set Setup and Connections

The diagram shows the gauge set connections for testing and charging:

1. Close manifold gauge set valves. Connect the center hose to an HFC-410A cylinder for liquid phase charging.
2. Connect the manifold gauge set's low pressure side to the suction line service port.
3. Connect the manifold gauge set's high pressure side to the liquid line service port.
4. Position the temperature sensor on the liquid line near the liquid line service port.

Determining Charge Method

START: Measure outdoor ambient temperature

WHEN TO CHARGE? Best in warm weather; can charge in colder weather.

CHARGE METHOD? Determined by metering device type and outdoor ambient temperature.

REQUIREMENTS: Sufficient heat load, indoor temperature between 70-80°F (21-26°C), connected manifold gauge set, and thermometers for ambient, liquid line, and suction line temperatures.

The diagram illustrates two methods: Subcooling (for outdoor ambient 65°F/18.3°C and above) and Weigh-In (for outdoor ambient 64°F/17.7°C and below).

Checking Air Flow at Indoor Coil

Check airflow using the Delta-T (DT) process. The procedure involves measuring entering air dry-bulb (A) and wet-bulb (B) temperatures to determine the desired DT from a chart. Then, measure the coil's dry-bulb entering and leaving air temperatures to find the temperature drop (TDrop = A - C). Compare TDrop to DT to determine if fan speed adjustment is needed. If the difference is within +3°, no adjustment is needed. If it's outside this range, increase or decrease airflow accordingly. Adjust fan speed per indoor unit instructions.

NOTE: Changing air flow affects temperatures; recheck to confirm DT is within +3°.

Refrigerant Charge per Line Set Length

Adjust the refrigerant charge based on line set length. For line sets longer than 4.6 m, add the specified amount; for shorter lines, subtract.

HFC-410A Subcooling Charge

START: Measure outdoor ambient temperature

USE SUBCOOLING METHOD: Block the outdoor coil if necessary (e.g., with cardboard) to achieve specific pressures (325-375 psig) for checking charge. If the measured value is MORE than shown, remove refrigerant. If LESS, add refrigerant.

Procedure:

1. Confirm proper airflow (Figure 19).
2. Compare unit pressures with Table 5 or 6.
3. Set thermostat for cooling load (70-80°F).
4. Connect gauge set.
5. Measure outdoor ambient temperature.
6. When heat demand is satisfied, set thermostat to cooling.
7. Allow temperatures and pressures to stabilize. Block outdoor coil if needed to maintain 325-375 psig.
8. Record liquid line temperature (LIQ°).
9. Measure liquid line pressure and determine saturation temperature (SAT°) from Table 7.
10. Calculate subcooling: SAT° - LIQ° = SC°.
11. Compare results with Tables 3 or 4.

Normal Operating Pressures

Tables 5 and 6 provide normal operating pressures (Liquid +10 Psig and Suction +5 Psig) for various TSA*S4 models at different outdoor ambient temperatures for 1-Phase and 3-Phase units, respectively. Table 7 provides HFC-410A temperature-to-pressure conversion.

System Operation

IMPORTANT Some scroll compressors have internal vacuum protectors that unload scrolls below 20 psig suction pressure, indicated by a hissing sound. The protector resets above 40 psig. Do not replace the compressor.

The outdoor unit and indoor blower cycle based on the thermostat. When the thermostat blower switch is ON, the indoor blower operates continuously.

HIGH PRESSURE SWITCH (S4): This unit has a high-pressure switch located in the liquid line of the compressor. It is a single pole, single throw, manual-reset switch that removes power from the compressor when discharge pressure exceeds a factory setting (590 ± 10 psi). The red cap on the manual-reset button is used to reset the switch.

Crankcase Heater (HR1): Prevents liquid refrigerant accumulation in the compressor. It is always on when the compressor is off. An optional crankcase heater thermostat (S40) is available.

Maintenance

Maintenance and service must be performed by a qualified installer or service agency. Checks should be performed at the beginning of each cooling season.

WARNING Electric shock hazard. Turn off electrical power before performing service or maintenance.

WARNING Improper installation, adjustment, alteration, service, or maintenance can cause injury, death, or property damage.

Outdoor Unit:

1. Fan motor is pre-lubricated and sealed.
2. Inspect connecting lines, joints, and coils for oil leaks.
3. Check all wiring for loose connections.
4. Verify correct voltage at the unit while operating.
5. Check amp draw on the outdoor fan motor.
6. Inspect and clean drain holes in the coil compartment base.

Outdoor Coil: Clean and inspect the outdoor coil. Flush with a water hose if necessary. Frequent cleaning may be needed for coils exposed to corrosive substances or debris (e.g., pet urine, cottonwood seeds, fertilizers, salts). Sea coast locations require frequent inspections due to corrosive salt air.

Indoor Unit:

1. Clean or change filters.
2. Blower motors are prelubricated and sealed.
3. Adjust blower speed for cooling if necessary, referring to the service manual for pressure drop tables.
4. For Belt Drive Blowers, check belt wear and tension.
5. Check all wiring for loose connections.
6. Check for correct voltage at the unit.
7. Check amp draw on the blower motor.

Indoor Coil: Clean the coil if necessary. Check connecting lines, joints, and coil for oil leaks. Clean the condensate line.

OWNER Maintenance: Outdoor unit coil cleaning should be done by a trained technician. The homeowner can perform some basic checks. A white residue on coil guards is a non-toxic byproduct and can be wiped off.

CAUTION Be aware of and use caution when working near metal edges and corners.

IMPORTANT Avoid prolonged exposure of the unit to treated water from sprinklers or soaker hoses, as it can corrode parts and diminish performance.

Cleaning Debris from Mesh (Figure 23): Describes how to remove the inner mesh screen for cleaning the outdoor coil, involving removing push pins.

Routine Maintenance: Clogged filters and blocked airflow reduce efficiency. Check air filters monthly and clean or replace as needed. Disposable filters should be replaced with the same type/size. Reusable foam filters should be cleaned with mild soap and water, rinsed, and dried completely.

NOTE: Filters and access panels must be in place during operation.

Lennox Branded Air Filters: Designed to remove airborne particles.

Indoor Unit Evaporator Coil: Equipped with a drain pan to collect condensate. Check the drain line for obstructions.

Thermostat Operation: Refer to the thermostat homeowner manual.

Start-Up and Performance Checklist

Preservice Check: Before calling for service, verify thermostat settings, ensure all electrical disconnects are ON, check for blown fuses/tripped breakers, confirm access panels are in place, and check the air filter. Note the unit model number if service is needed.

Accessories: Refer to Lennox TSA*S4 Engineering Handbook and Lennox Commercial Price Book for more information.

The checklist section provides fields for Job Name, Location, Installer, Unit Model No., Serial No., Nameplate Voltage, Rated Load Ampacity, Electrical Connections, Indoor Filter, Supply Voltage, Indoor Blower RPM, S.P. Drop, Outdoor Coil Entering Air Temp., Discharge Pressure, Suction Pressure, Refrigerant Charge, Refrigerant Lines, Service Valves, and Thermostat settings.