American Standard Thermostat ASYSTAT500C Manual

The American Standard ASYSTAT500C is a programmable digital thermostat designed for precise temperature control of residential heating and cooling systems. It features a backlit LCD display, 7-day programming capability, automatic changeover between heating and cooling modes, filter change reminder, system status indicators, and compatibility with most 24VAC HVAC systems. Below are key sections for installation, programming, operation, and troubleshooting.

Features at a Glance

Key components: Backlit LCD display, Menu/Select button, Up/Down arrows, System switch (Heat/Cool/Off/Auto), Fan switch (Auto/On), Hold button, Program button.

Installation & Wiring

Turn off power to HVAC system at circuit breaker before installation.

1. Remove old thermostat: Label wires, disconnect from terminals.
2. Mount new baseplate: Level and secure to wall using provided screws.
3. Connect wires: Match labeled wires to corresponding terminals (R, W, Y, G, C, etc.).
4. Attach thermostat: Align and snap onto baseplate.
5. Install batteries: Insert 2 AA batteries for backup power.
6. Restore power: Turn circuit breaker back on.

WARNING! Electrical shock hazard. Ensure power is completely off before handling wires. If unsure, consult a qualified HVAC technician.

First-Time Setup

After installation and power restoration, configure initial settings.

1. Set time and day: Press MENU, navigate to CLOCK SETTINGS, enter current time and day.
2. Select temperature format: Choose between Fahrenheit (°F) or Celsius (°C).
3. Configure system type: Set for conventional or heat pump system in INSTALLER SETUP.
4. Set filter reminder interval: Default is 90 days; adjust based on your filter type.
5. Test system: Manually activate heating and cooling to verify proper operation.

CAUTION! Incorrect wiring or configuration can damage HVAC equipment. Verify all connections match your system type.

Specifications

• Power Requirements: 24VAC from HVAC system; 2 AA batteries for backup.
• Temperature Range: Heating: 40°F to 90°F (4°C to 32°C); Cooling: 50°F to 99°F (10°C to 37°C).
• Display: Backlit LCD with adjustable timeout (5-30 seconds).
• Programming: 4 time periods per day (Wake, Leave, Return, Sleep).
• Accuracy: ±1°F (±0.5°C).
• Compatibility: 1-2 stage heating, 1-2 stage cooling, heat pump with auxiliary heat.
• Operating Environment: 32°F to 122°F (0°C to 50°C); 0-90% RH non-condensing.
• Wiring: Standard thermostat terminals: R, Rc, Rh, W, Y, G, O/B, C, etc.

Controls and Display

Front panel includes MENU/SELECT button, Up/Down arrows, SYSTEM switch, FAN switch, HOLD, and PROGRAM buttons.

Display Icons: Flame (Heating), Snowflake (Cooling), Fan (Fan Running), Clock (Program Active), Lock (Keypad Locked), Filter (Filter Change Reminder).

Menu Navigation: Press MENU to access CLOCK, SCHEDULE, SETTINGS, INSTALLER SETUP. Use arrows to navigate, SELECT to choose. Temperature Adjustment: Press Up/Down arrows to change setpoint. System Modes: SYSTEM switch positions: OFF, HEAT, COOL, AUTO (automatic changeover). Fan Control: FAN switch: AUTO (runs with system), ON (continuous operation).

Programming Schedule

Create custom temperature schedules for energy savings.

1. Press PROGRAM button to enter programming mode.
2. Select day(s): Choose ALL DAYS, WEEKDAYS, WEEKEND, or individual days.
3. Set periods: For each day, program 4 periods: WAKE, LEAVE, RETURN, SLEEP.
4. Set temperatures: For each period, set desired heating and cooling setpoints.
5. Save: Press MENU/SELECT to save and exit.
6. Activate: Ensure PROGRAM icon is displayed on screen for schedule to run.

Tip: Use recommended energy-saving settings: 68°F (20°C) heating when home, 62°F (17°C) when away or sleeping; 78°F (26°C) cooling when home, 85°F (29°C) when away.

Operating Modes

SYSTEM switch positions determine operation mode.

1. HEAT: Thermostat controls heating system only. Displays flame icon when active.
2. COOL: Thermostat controls cooling system only. Displays snowflake icon when active.
3. AUTO: Automatic changeover between heating and cooling based on setpoints.
4. OFF: HVAC system is off (fan may still run if set to ON).

Hold Function: Press HOLD to temporarily override programmed schedule. Display shows HOLD icon. Press HOLD again or press PROGRAM to resume schedule. Fan Control: FAN AUTO runs only when heating/cooling is active. FAN ON runs continuously for air circulation.

Advanced Settings

Access INSTALLER SETUP by pressing MENU for 5 seconds (default password 0000).

Configuration Options: System type (conventional/heat pump), Stages (1/2 heat, 1/2 cool), Compressor protection (minimum off time), Temperature differential (heating/cooling), Backlight timeout, Filter reminder interval, Keypad lock, Temperature calibration, Fahrenheit/Celsius selection.

WARNING! Installer settings affect system operation. Incorrect settings may cause poor performance or equipment damage. Refer to HVAC system specifications before changing.

Care & Maintenance

Clean display with soft, dry cloth only. Do not use liquids or cleaners.

1. Battery replacement: Replace AA batteries annually or when low battery icon appears.
2. Filter reminder: Reset after filter change by navigating to FILTER SETTINGS in menu.
3. Dust removal: Gently vacuum around thermostat to prevent dust buildup.

CAUTION! Do not spray cleaning solutions directly on thermostat. Ensure power is off before removing for cleaning.

Regulatory Information

FCC Part 15: Class B digital device; complies with interference limits for residential use. UL 873 certified for safety. Copyright © American Standard Heating & Air Conditioning. For support, visit www.americanstandard.com or contact 1-800-228-2962. This product may be covered by one or more patents. See www.americanstandard.com/patents.

Troubleshooting

Reset to Factory Defaults: Press MENU for 10 seconds, select RESET ALL SETTINGS.

Service: 1-800-228-2962; www.americanstandard.com