American Standard HVAC Mitsubishi Electric NAXSKS18A112A Series Manual

The American Standard HVAC Mitsubishi Electric NAXSKS18A112A Series is a high-efficiency, multi-zone ductless mini-split heat pump system designed for residential and light commercial applications. This system features inverter-driven compressor technology for precise temperature control, energy savings, and quiet operation. Below are key sections covering safety, features, installation, setup, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: Outdoor condensing unit, Indoor wall-mounted evaporator(s), Wireless remote controller, Refrigerant piping, Drain hose, and Communication wiring.

Installation Requirements

Unpack and inspect all components. Ensure proper location for indoor and outdoor units.

1. Outdoor Unit Placement: Install on stable, level surface with adequate clearance (min 12 inches on all sides).
2. Indoor Unit Placement: Mount on interior wall, 7-8 feet from floor, away from direct sunlight and heat sources.
3. Refrigerant Piping: Connect pre-charged linesets between units following length limitations (see specifications).
4. Electrical Connections: Connect to dedicated circuit per local codes. Outdoor unit requires 208/230V power.
5. Drainage: Route condensate drain hose to proper drainage point with continuous downward slope.

WARNING! Installation must be performed by qualified HVAC technician only. Improper installation can cause equipment damage, personal injury, or void warranty.

First-Time Setup & Commissioning

After installation, power on system and perform initial setup.

1. Power Up: Turn on circuit breaker for outdoor unit, then indoor unit.
2. Remote Control Setup: Install batteries in remote. Point directly at indoor unit's signal receiver.
3. Test Operation: Select COOL mode, set temperature 10°F below room temp, verify cold air output.
4. Test Heating: Select HEAT mode, set temperature 10°F above room temp, verify warm air output.
5. Check Drainage: Verify condensate is draining properly from indoor unit.
6. Configure Settings: Set clock, timer functions, and preferred default modes via remote.

CAUTION! Allow system to complete startup sequence. Do not switch modes rapidly. If error code appears, refer to troubleshooting section.

Technical Specifications

• Model Series: NAXSKS18A112A
• System Type: Ductless Mini-Split Heat Pump
• Cooling Capacity: 18,000 BTU/h
• Heating Capacity: 20,000 BTU/h
• Power Supply: 208/230V, 1 Phase, 60Hz
• Refrigerant: R-410A
• SEER Rating: Up to 20.5
• HSPF Rating: Up to 10.0
• Operating Temperature Range: Cooling: 14°F to 115°F; Heating: -13°F to 75°F
• Indoor Noise Level: As low as 19 dB(A)
• Outdoor Noise Level: As low as 50 dB(A)
• Maximum Piping Length: 82 feet (with proper sizing)
• Maximum Height Difference: 50 feet (outdoor unit above/below indoor unit)

System Controls & Settings

Primary control via wireless remote. Indoor unit also has manual buttons for basic operation.

Remote Control Functions: POWER, MODE (Auto, Cool, Heat, Dry, Fan), TEMP ▲/▼, FAN SPEED (Auto, Low, Medium, High), TIMER, SWING, SLEEP, FILTER RESET, CLOCK SET.

Operation Modes: - AUTO: System automatically selects heating or cooling based on room temperature. - COOL: Cooling operation with adjustable temperature (61°F - 88°F). - HEAT: Heating operation with adjustable temperature (61°F - 88°F). - DRY: Dehumidification mode for reducing humidity. - FAN: Circulates air without heating or cooling.

Advanced Settings (via remote): - SLEEP Mode: Gradually adjusts temperature for comfortable sleeping. - TIMER: Program on/off times (daily or one-time). - LOUVER Direction: Manual or automatic vertical/horizontal airflow control. - FILTER Reset: Resets filter cleaning reminder after maintenance.

Connecting Indoor & Outdoor Units

Proper connection is critical for system performance and longevity.

1. Refrigerant Lines: Connect liquid and vapor lines using flare fittings. Torque to specifications.
2. Electrical Wiring: Connect communication cable between indoor and outdoor units per wiring diagram.
3. Drain Hose: Attach to indoor unit drain port, route to drainage with continuous downward slope.
4. Vacuum & Pressure Test: Evacuate system to 500 microns, hold vacuum, then release refrigerant charge.

Tip: Always use proper tools (torque wrench, vacuum pump, manifold gauges) and follow manufacturer specifications exactly.

Operation Modes & Functions

System offers multiple operation modes for comfort and efficiency.

1. Starting the System: Press POWER on remote. Select desired MODE.
2. Temperature Setting: Use TEMP ▲/▼ to set desired temperature (display shows set point).
3. Fan Speed Adjustment: Press FAN button to cycle through Auto, Low, Medium, High speeds.
4. Louver Control: Press SWING to activate auto-swing or use directional buttons for fixed position.
5. Timer Programming: Press TIMER, set desired on/off time, then press TIMER again to confirm.
6. Sleep Mode: Press SLEEP - temperature gradually adjusts over 7 hours for energy savings.
7. Emergency Operation: If remote is lost, use manual buttons on indoor unit for basic functions.

WARNING! Do not set heating temperature too high or cooling temperature too low. Extreme settings reduce efficiency and may cause compressor short-cycling.

Maintenance & Filter Care

Regular maintenance ensures optimal performance and longevity.

1. Air Filter Cleaning: Remove filter every 2 weeks (more often in dusty environments). Wash with mild detergent, rinse thoroughly, dry completely before reinstalling.
2. Outdoor Unit Maintenance: Keep area clear of debris, leaves, and snow. Clean coil annually with soft brush (do not use pressure washer).
3. Indoor Unit Cleaning: Wipe exterior with soft, dry cloth. Do not use abrasive cleaners or water spray.
4. Pre-Season Check: Before cooling/heating season, verify proper operation, check for unusual noises, ensure adequate airflow.
5. Professional Service: Schedule annual maintenance by qualified technician to check refrigerant charge, electrical connections, and system performance.

CAUTION! Always turn off power at circuit breaker before performing any maintenance. Do not attempt to service refrigerant system - licensed professional required.

Regulatory & Compliance Information

This product complies with applicable U.S. federal regulations and standards. EPA Section 608: Contains refrigerant - service must be performed by certified technician. UL Listed: Meets safety standards for electrical equipment. ENERGY STAR®: Qualified for energy efficiency. California Proposition 65 Warning: This product may contain chemicals known to cause cancer or reproductive harm. For technical support or warranty service, contact American Standard Heating & Air Conditioning at 1-800-926-9666 or visit www.americanstandardair.com.

Troubleshooting Guide

Reset Procedure: Turn off at circuit breaker for 5 minutes, then restore power to reset control board.

Service Contact: For warranty service or technical support: 1-800-926-9666 or www.americanstandardair.com