American Standard Thermostat ACONT103 Manual

The American Standard ACONT103 is a non-programmable digital thermostat designed for single-stage heating and cooling systems. It features a large, easy-to-read backlit display, intuitive up/down temperature control, system mode selection (Heat, Cool, Off, Auto), fan control (Auto, On), and a built-in temperature hold function. Compatible with most 24VAC systems, it requires common (C) wire power or battery operation (optional). Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

Features at a Glance

Key components: Large backlit LCD display, Mode button, Fan button, Up/Down temperature buttons, System switch, Battery compartment.

Installation

Turn off HVAC system power at circuit breaker. Remove old thermostat and inspect wiring.

1. Mount subbase: Level and secure to wall using provided screws.
2. Connect wires: Match labeled terminals (R, W, Y, G, C) to existing wires; use wire nuts if needed.
3. Attach thermostat: Align pins and snap onto subbase.
4. Restore power: Turn circuit breaker back on.
5. Install batteries: Insert 2 AA batteries for backup (optional if C wire present).

WARNING! Electrical shock hazard. Always turn off power before installation. If unsure, consult a qualified HVAC technician.

First-Time Setup

After installation and power restoration, configure basic settings.

1. Set temperature scale: Press and hold UP and DOWN buttons for 3 seconds to toggle °F/°C.
2. Set system mode: Use MODE button to select Heat, Cool, Off, or Auto.
3. Set fan mode: Use FAN button to select Auto or On.
4. Adjust temperature: Use UP/DOWN buttons to set desired temperature.
5. Program filter reminder: Press and hold FAN button for 5 seconds, then use UP/DOWN to set months (1-12).

CAUTION! Ensure correct wiring before restoring power to prevent equipment damage.

Specifications

• Type: Non-programmable digital thermostat.
• Display: Backlit LCD with temperature and icons.
• Control: Single-stage heating and cooling.
• Temperature Range: 40°F to 99°F (4°C to 37°C).
• Accuracy: ±1°F (±0.5°C).
• Power Requirements: 24VAC, 20VA max; or 2 AA batteries (backup).
• Terminals: R, W, Y, G, C (common).
• Operating Environment: 32°F to 105°F (0°C to 40°C), 0-90% RH non-condensing.
• Mounting: Standard 2" x 3" subbase.
• Warranty: 5-year limited warranty.

Controls and Settings

Front panel buttons: MODE, FAN, UP, DOWN. Display shows set temperature, room temperature, mode icons, and filter reminder.

Mode Selection: Press MODE to cycle through Heat (flame icon), Cool (snowflake), Off (blank), Auto (both icons). Auto mode automatically selects heating or cooling based on room temperature.

Fan Control: Press FAN to toggle between Auto (fan icon off) and On (fan icon on). In Auto, fan runs only when heating/cooling is active. In On, fan runs continuously.

Temperature Adjustment: Press UP or DOWN to change setpoint. Display shows set temperature briefly, then returns to room temperature.

Temperature Hold: To hold current temperature indefinitely, adjust setpoint. To resume scheduled program (if applicable), press and hold UP and DOWN for 3 seconds.

Wiring Configuration

Standard terminal designations for single-stage systems:

1. R (Red): 24VAC power from transformer.
2. W (White): Heat control (connects to furnace/heat pump).
3. Y (Yellow): Cool control (connects to air conditioner).
4. G (Green): Fan control (connects to blower relay).
5. C (Blue/Black): Common wire for 24VAC return (provides continuous power).

Note: If no C wire is present, install 2 AA batteries for thermostat power. Batteries may need replacement every 12 months.

Tip: Label wires before removing old thermostat to ensure correct reconnection.

Operating Modes

Four system modes available:

1. Heat Mode: Thermostat calls for heat when room temperature drops below setpoint. Furnace or heat pump heating stage activates.
2. Cool Mode: Thermostat calls for cooling when room temperature rises above setpoint. Air conditioner activates.
3. Off Mode: Heating and cooling systems disabled. Fan can still be set to On for circulation.
4. Auto Mode: Thermostat automatically switches between heating and cooling to maintain setpoint. Requires separate heat and cool setpoints (adjustable via UP/DOWN).

WARNING! Do not switch between Heat and Cool modes rapidly; allow 5 minutes for system pressure to equalize.

Advanced Functions

Filter Change Reminder: Program interval (1-12 months). When time elapses, filter icon flashes. To reset, press and hold FAN button for 5 seconds, then press UP once.

Temperature Calibration: If room temperature reading is inaccurate, adjust calibration. Press and hold MODE and DOWN for 5 seconds, then use UP/DOWN to offset (-5°F to +5°F). Press MODE to save.

Battery Alert: When batteries are low, battery icon flashes. Replace with fresh AA batteries within 30 days to prevent loss of settings.

Care & Maintenance

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

Replace air filter according to reminder to maintain system efficiency.

Check batteries annually if used; replace if low battery icon appears.

CAUTION! Do not spray cleaning agents directly on thermostat. Ensure unit is dry before restoring power.

Regulatory Information

FCC Part 15: Class B digital device; complies with interference limits for residential use. UL Listed. 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 website for details.

Troubleshooting

Reset: Remove batteries and disconnect power for 30 seconds, then reconnect.

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