American Standard Thermostat CERATHERM T050.110 Manual

The American Standard CERATHERM T050.110 is a programmable digital thermostat designed for precise temperature control of heating and cooling systems. It features a backlit LCD display, 7-day programming capability, temperature hold functions, system mode selection (Heat/Cool/Auto/Off), fan control (Auto/On), and filter change reminder. It is compatible with most 24VAC single-stage HVAC systems. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

1. Features at a Glance 2. Installation 3. First-Time Setup 4. Specifications 5. Controls and Settings 6. Connecting to HVAC System 7. Programming Schedule 8. Energy Saving Features 9. Care & Cleaning 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Backlit LCD Display, Mode Button, Fan Button, Up/Down Temperature Buttons, Hold Button, Program Button, Menu/Set Button.

Feature	Description
LCD Display	Shows current time, temperature, system status, and programming info
7-Day Programming	Allows different schedules for each day of the week
Temperature Hold	Temporarily overrides programmed schedule
System Mode	Select Heat, Cool, Auto (automatic changeover), or Off
Fan Control	Set fan to Auto (runs with system) or On (continuous)
Filter Change Reminder	Alerts when it's time to replace HVAC filter
Backlight	Illuminates display when any button is pressed
Battery Backup	Uses 2 AA batteries to retain settings during power loss
Temperature Range	40°F to 99°F (Heat), 50°F to 99°F (Cool)
Compatibility	24VAC single-stage heating and cooling systems

Installation

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

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

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

First-Time Setup

After installation and power restoration, configure initial settings.

Set time and day: Press MENU/SET, use arrows to adjust, press SET to confirm.
Select temperature format: In MENU, choose Fahrenheit (°F) or Celsius (°C).
Set system type: Configure for conventional or heat pump system if applicable.
Configure filter reminder: Set interval (e.g., 90 days) in MENU > FILTER.
Review default program: Press PROGRAM to view factory schedule; adjust as needed.

CAUTION! Ensure correct system configuration to prevent equipment damage.

Specifications

Power: 24VAC from HVAC system; 2 AA battery backup.
Display: Backlit LCD.
Programming: 7-day, 4 periods per day.
Temperature Control: 1°F (0.5°C) increments.
Operating Temp: 32°F to 105°F (0°C to 40°C).
Relative Humidity: 0% to 90% non-condensing.
Terminals: R, Rc, W, Y, G, C, O/B, Aux/E.
Dimensions: 5.5" H x 3.5" W x 1" D (approx.).
Warranty: 5-year limited warranty.

Controls and Settings

Access functions via front buttons. Mode: Cycle through Heat, Cool, Auto, Off. Fan: Toggle Auto/On. Temp Arrows: Adjust setpoint. Hold: Temporarily override schedule. Program: Enter programming mode. Menu/Set: Access system settings.

Menu Settings: Time/Day, Temperature Format (°F/°C), System Type (Conventional/Heat Pump), Filter Change Interval, Calibration (adjust temperature reading if needed), Reset (restore factory defaults).

Connecting to HVAC System

Ensure compatibility with 24VAC single-stage systems.

Identify wires: Common labels: R (24VAC Power), W (Heat), Y (Cool), G (Fan), C (Common).
Connect to baseplate: Insert stripped wire into corresponding terminal; tighten screw.
For heat pumps: Additional O/B terminal for reversing valve.
Check connections: Ensure wires are secure and not touching each other.

Tip: Take a photo of old thermostat wiring before removal for reference.

Programming Schedule

Create a custom 7-day schedule for energy savings.

Press PROGRAM button.
Select day: Use arrows to choose day or copy schedule to other days.
Set periods: Up to 4 periods per day (Wake, Leave, Return, Sleep).
For each period: Set time and desired temperature (Heat or Cool setpoint).
Save: Press MENU/SET to confirm and exit.
Override: Press HOLD to temporarily adjust temperature; schedule resumes at next programmed period.

WARNING! Do not set extreme temperatures that could cause system short-cycling or discomfort.

Energy Saving Features

Programmable schedule reduces energy use when away or asleep. Adaptive Recovery: Learns system cycle time to reach setpoint by programmed time. Temperature Limits: Prevents excessive heating/cooling setpoints. Filter Reminder: Ensures efficient system operation.

Care & Cleaning

Turn off power before cleaning. Use soft, dry cloth to wipe display and casing. Do not use liquids or abrasive cleaners.

CAUTION! Do not spray cleaners directly on thermostat. Avoid excessive moisture.

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.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Blank display	Power loss / dead batteries	Check circuit breaker; replace AA batteries.
System not turning on	Incorrect wiring / mode setting	Verify wiring connections; ensure Mode is set to Heat or Cool.
Incorrect temperature reading	Location / calibration	Relocate away from heat sources; use calibration in MENU.
Schedule not following	Hold active / programming error	Cancel HOLD function; review and reprogram schedule.
Fan runs continuously	Fan set to ON	Press FAN button to switch to AUTO.

Reset: Menu > System > Reset to Factory Defaults.

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