Honeywell Home T4 Pro Thermostat User Manual

Honeywell Home T4 Pro Thermostat

This manual provides instructions for the Honeywell Home T4 Pro Programmable Thermostat, models TH4110U2005 and TH4210U2002.

The thermostat display shows the current time, indoor temperature, setpoint temperature, system mode (Heat, Cool, Auto, Off, Em. Heat), and fan mode (Auto, On).

Thermostat Controls:

• The screen wakes up by pressing any of the five buttons.
• If powered by a C wire, the screen stays lit for 45 seconds after changes.
• If powered by battery only, the screen stays lit for 8 seconds.
• Screen light may always be on depending on installation.

Customer Assistance: For assistance, visit Honeywellhome.com/support.

Package Includes:

• T4 Pro Thermostat
• UWP™ Mounting System
• Decorative Cover Plate
• Screws and Anchors
• 2 AA Batteries
• Thermostat Literature

System Operation Settings

Press the Mode button to cycle through available System modes:

• Auto
• Heat
• Cool
• Off
• Em. Heat (TH4210U only)

Available modes may vary by model and system settings.

Fan Operation Settings

Press the Fan button to cycle through available Fan modes:

• Auto: Fan runs only when the heating or cooling system is on.
• On: Fan is always on.

Available fan modes may vary with system settings.

Set the Time and Date

Time:

1. Press Menu, then press + to go to TIME. Press Select.
2. Press + or - to choose between 12 or 24-hour format. Press Select.
3. Use + or - to adjust the hour. Press Select.
4. Use + or - to adjust the minutes. Press Select to exit the Time menu.

Date:

1. If previously setting time, continue to Step 2. If at the Home screen, press Menu.
2. Press + or - to go to DATE. Press Select.
3. Use + or - to adjust the year. Press Select.
4. Use + or - to adjust the month. Press Select.
5. Use + or - to adjust the date. Press Select to save and exit the Date menu.

Program Schedule

You can program four time periods each day: Wake, Away, Home, and Sleep. Different settings can be applied for weekdays and weekends. Pre-set schedules are recommended to reduce expenses.

• Wake: Time you wake up and desired morning temperature.
• Away: Time you leave home and energy-saving temperature while away.
• Home: Time you return home and desired evening temperature.
• Sleep: Time you go to bed and energy-saving temperature overnight.

To Adjust Program Schedules:

1. Press Menu.
2. PROG is displayed. Press Select. ON is displayed. (If not using a schedule, press + or - to display OFF, then press Select.) Press Select.
3. Press + or - to select the day or set of days to edit. Press Select.
4. Press + or - to select a schedule period (Wake, Away, Home, Sleep). Press Select.
5. ON is displayed. Press Select to keep the schedule period active. Or press + and then Select to turn off the schedule period.
6. The time starts blinking. Press + or - to adjust the schedule period start time. Press Select.
7. The temperature starts blinking. Press + or - to adjust the "Heat" setpoint temperature. Press Select. Press + or - to adjust the "Cool" temperature setpoint. Press Select.
8. Repeat steps 4-7 for remaining schedule periods.
9. Press Home to save and return to the home screen.
10. Schedules can be adjusted and turned ON or OFF by returning to Menu and following the steps above.

Program Schedule Override (Temporary)

1. Press + or - to adjust the temperature to the desired setpoint.
2. The new setpoint will be held until the next scheduled time period begins.
3. To cancel the Temporary Hold, press + or -, then press Cancel.

Program Schedule Override (Permanent)

1. Press + or - to adjust the temperature.
2. TEMPORARY HOLD is displayed and the setpoint temperature flashes. While flashing, press the Hold (Mode) button to change to Permanent Hold.
3. To cancel the Permanent Hold, press + or -, then press Cancel.

Setting Degrees Fahrenheit (F) or Celsius (C)

1. Press Menu.
2. Press + or - to go to F / C. Press Select.
3. Press + or - for F or C. Press Select to save and exit the F / C menu.

Adjusting Keypad Lockout

1. Press Menu on the thermostat.
2. Press - or + to go to LOCK. Press Select.
3. Press - or + to go to OFF (Unlocked), PART (Partial lockout, temperature adjustable), or ON (No access). Press Select.
4. To unlock the keypad, press the CENTER button and enter the password "1234". Press + or - to change the first digit, then press Select. Repeat for the remaining digits. Press Select again after the last digit.
5. The keypad will unlock. If the code is incorrect, "--" will flash. Press Back to re-enter the code.

Note: Keypad lockout may only be available in the installer menu on some models.

Adjusting Idle Backlight Display Brightness

1. Press Menu on the thermostat.
2. Press - or + to go to LITE. Press Select.
3. The current brightness setting (1-5) is displayed.
4. Press - or + to adjust backlight brightness.
5. Press Select to save and exit the LITE menu.

Note: Backlight is only displayed if the C (common) wire is connected.

Adaptive Intelligent Recovery

The T4 Pro Thermostat learns how long your system takes to reach a set temperature and turns on the heating or cooling system earlier to ensure comfort at the expected time.

Built-in Compressor Protection

To prevent damage from premature compressor restarts, this feature enforces a waiting period before the compressor restarts. The display will flash "Cool On" or "Heat On" during this period. The compressor will restart automatically once the safe wait time has elapsed.

Battery Replacement

Batteries provide backup power if the thermostat is wired for AC power. If not wired for AC power, batteries are required. Replace batteries immediately when the low battery icon appears (approximately two months before depletion). It is recommended to replace batteries annually or before leaving home for over a month. Replacing batteries within two minutes preserves the time and day settings; other settings are permanently stored.

Note: Alkaline batteries are recommended.

Alerts

An alert icon ⚠️ appears on the Home screen when there is an alert or reminder.

Low Battery Warning:

• The thermostat displays BATT, the alert icon ⚠️, and the battery icon ? when batteries need replacement.
• When battery power is very low, the backlight is disabled to conserve power.
• When battery power is critically low, only BATT, the alert icon ⚠️, and the battery icon ? are displayed.

Air Filter Reminder:

1. The alert icon ⚠️ appears on the Home screen.
2. Press Menu, then press - until ALRT is displayed.
3. Press Select to view alerts.
4. The message REPL (REPLACE AIR FILTER) appears.
5. The reminder can be snoozed or cleared. Resideo recommends changing the air filter before clearing the reminder.
6. To snooze, press Select. SNZE (SNOOZE) appears.
7. Press Select again to snooze the reminder for 7 days.
8. To clear, press Select, then press - to go to CLER (Clear).
9. Press Select to clear the air filter reminder.

Snoozing and Clearing Alerts or Reminders:

1. Press Menu, then press - until ALRT is displayed.
2. Press Select to display which alert(s) are present.
3. The word SNZE (SNOOZE) appears.
4. Press Select again to snooze the reminder for 7 days.
5. To clear the alert, press Select, then press - to go to CLER (Clear).
6. Press Select to clear the reminder.

Note: Some alerts cannot be snoozed or cleared. Contact a local heating and cooling professional if this occurs, as the system may require service.

Troubleshooting

Display is blank:

• Check and reset the circuit breaker if necessary.
• Ensure the power switch for the heating & cooling system is on.
• Ensure the furnace door is closed securely.
• Ensure fresh AA alkaline batteries are correctly installed.

Heating or cooling system does not respond:

• Set system to Heat and ensure the desired temperature is higher than the indoor temperature.
• Set system to Cool and ensure the desired temperature is lower than the indoor temperature.
• Check and reset the circuit breaker if necessary.
• Ensure the power switch for the heating & cooling system is on.
• Ensure the furnace door is closed securely.
• Wait 5 minutes for the system to respond.

Temperature settings do not change:

• If the display shows "unlock", refer to the keypad lockout instructions.
• Verify you are in the correct mode (Heat, Cool, Em Heat, or Auto).
• If you cannot set the heat from 40°F to 90°F (4.5°C to 32°C) or cool from 50°F to 99°F (10°C to 37°C), range-stops may be restricting your settings. Consult your installer.

"Cool On" or "Heat On" is flashing:

The compressor protection feature is active. Wait 5 minutes for the system to restart safely to prevent compressor damage.

Electrical Ratings

Refer to the product specifications for detailed electrical ratings.

5-Year Limited Warranty

For warranty information, visit Honeywellhome.com/support.

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