American Standard Thermostat Ceratherm T203.730 Manual

The American Standard Ceratherm T203.730 is a programmable electronic thermostat designed for precise temperature control of heating and cooling systems. It features a backlit LCD display, 7-day programming flexibility, automatic or manual changeover, adjustable temperature limits, filter change reminder, and system status indicators. Compatible with most 24VAC HVAC systems including single-stage heat/cool, heat pump, and multi-stage configurations. Below are key sections for safety, features, installation, programming, operation, and troubleshooting.

Features at a Glance

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

Installation

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

1. Remove old thermostat: Label wires before disconnecting.
2. Mount new baseplate: Level and secure to wall using provided screws.
3. Connect wires: Match labeled terminals (R, C, W, Y, G, O/B, etc.) to corresponding wires.
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. 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 mode: Press MODE to select Heat, Cool, Auto, or Off.
2. Set fan: Press FAN for Auto (fan runs with system) or On (continuous).
3. Set temperature: Use Up/Down arrows to adjust setpoint.
4. Configure system type: Access installer menu to set for conventional or heat pump.
5. Set clock and day: Access time settings in menu.
6. Enable/disable features: Set temperature limits, filter reminder, keypad lock.

CAUTION! Ensure correct system configuration to prevent equipment damage.

Specifications

• Power: 24VAC from HVAC system; 2 AA battery backup.
• Temperature Range: 40°F to 99°F (4°C to 37°C).
• Temperature Accuracy: ±1°F (±0.5°C).
• Display: Backlit LCD with °F/°C selectable.
• Programming: 4 periods per day, 7-day customizable schedule.
• Compatibility: 1H/1C conventional, 2H/2C multi-stage, heat pump with auxiliary heat.
• Terminals: R, C, W, Y, G, O/B, AUX/E, L (for common wire, heat/cool stages, fan, reversing valve).
• Operating Environment: 32°F to 122°F (0°C to 50°C); 0-90% RH non-condensing.
• Dimensions: Standard thermostat size for wall plate.

Controls and Settings

Front panel buttons: MODE, FAN, HOLD, PROGRAM, MENU, Up/Down arrows.

Basic Operation: Press MODE to cycle Heat/Cool/Auto/Off. Press FAN for Auto/On. Adjust temperature with arrows. HOLD maintains current setpoint indefinitely. PROGRAM accesses schedule. MENU accesses advanced settings.

Installer Menu (accessed by specific button sequence): Configure system type (conventional/heat pump), stage configuration, compressor protection delay, temperature calibration, filter reminder interval, temperature limits.

User Menu: Set clock, daylight saving, display format (°F/°C), keypad lock, restore factory defaults.

Wiring Configuration

Standard terminal designations for HVAC control.

1. R/Rc: 24VAC power for cooling (Rc) or combined power (R).
2. C: Common wire for continuous power (required for some features).
3. W/W1/W2: Heat stage 1 and 2.
4. Y/Y1/Y2: Cooling/compressor stage 1 and 2.
5. G: Fan relay control.
6. O/B: Reversing valve for heat pump (O for cool, B for heat).
7. AUX/E: Auxiliary or emergency heat.
8. L: System indicator light (optional).

Tip: Refer to HVAC system manual and existing wiring. Take photo before disconnecting old thermostat.

Programming Schedule

Create energy-saving schedule with up to 4 time/temperature periods per day.

1. Press PROGRAM button.
2. Select day: Choose individual day, weekday/weekend, or all 7 days.
3. Set first period: Use arrows to set wake time and temperature.
4. Set subsequent periods: Repeat for Leave, Return, Sleep (periods 2-4).
5. Review and save: Press PROGRAM to exit and save schedule.
6. Override temporarily: Adjust temperature with arrows; system returns to schedule at next period.
7. Hold indefinitely: Press HOLD to maintain current temperature until manually canceled.

WARNING! Do not set extreme temperature differentials that may cause system short-cycling.

Advanced Features

Automatic Changeover: In Auto mode, thermostat automatically selects heating or cooling to maintain comfort range. Temperature Limits: Set minimum heat and maximum cool temperatures in installer menu. Filter Reminder: Program interval (30-365 days); reminder icon appears when due. Keypad Lock: Prevent unauthorized changes (press and hold MENU for 5 seconds). Compressor Protection: Minimum 5-minute off-time between cycles (configurable).

Care & Maintenance

Clean display with soft, dry cloth. Do not use liquids or cleaners. Replace batteries annually or when low battery icon appears. Replace HVAC filter when reminder appears or per manufacturer schedule.

CAUTION! Do not spray cleaning fluids 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 Listed: Meets safety standards. Copyright © American Standard Heating & Air Conditioning. For support, visit www.americanstandardair.com or contact 1-800-228-2962. Dispose of batteries properly according to local regulations.

Troubleshooting

Reset: Menu > Restore Defaults (erases all custom settings).

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