Programmable Thermostat

If you're locked out or need to adjust settings, please refer to these instructions

Alerts Batteries Fan Settings System Settings Lock Schedule Set Date/Time Temp/Perm Hold Troubleshoot

Thermostat controls

T4 Controls

The screen will wake up by pressing any of the five buttons. If powered by the C wire, the screen stays lit for 45 seconds after you complete changes. If powered by battery only, the screen stays lit for 8 seconds. Depending on how your 
thermostat was installed, the screen light may always be on.

 


 

System operation settings

  1. Press the Mode button to cycle to the next available System mode.
  2. Cycle through the modes until the required System mode is displayed and leave it to activate.
System modes:
  • Auto
  • Heat
  • Cool
  • Off
  • Em. Heat (TH4210U only)
T4 System Op

NOTE: Available System modes vary by model and system settings.

Fan operation settings

  1. Press the Fan button to cycle to the next available Fan mode.
  2. Cycle through the modes until the required Fan mode is displayed and leave it to activate.
Fan Modes:
  • Auto: Fan runs only when the heating or cooling system is on.
  • On: Fan is always on.

 

T4 Fan Op

Set the time and date

Time

  1. Press Menu, and then press + to go to TIME. Press Select.
  2. Press + or - to choose between 12 or 24 hour.
    Press Select.
  3. Use + or - to adjust the hour. Press Select.
  4. Use + or - to adjust the minutes. Press Select to exit Time menu.
T4 Time

Date

  1. If previously setting time, continue to Step 2. If at the Home screen, press Menu on your thermostat.
  2. Press + or - to go to DATE. Press Select.
  3. Use + or to adjust year. Press Select.
  4. Use + or - to adjust month. Press Select
  5. Use + or - to adjust Date. Press Select to save and exit Date menu.
T4 Date

 

Program Schedule

You can program four time periods each day, with different settings for weekdays and weekends. We recommend the pre-sets (shown in the table below), since they can reduce your heating/cooling expenses.

Wake - Set to the time you wake up and the temperature you want during the morning, until you leave for the day.
Away - Set to the time you leave home and the temperature you want while you are away (usually an energy-saving level).
Home - Set to the time you return home and the temperature you want during the evening, until bedtime.
Sleep - Set to the time you go to bed and the temperature you want overnight (usually an energy-saving level).
T4 Schedule Recommendations

NOTE: To temporarily or permanently override any of the above program schedules, see the "Program Override" section below.

To adjust program schedules

  1. Press Menu on your thermostat.
  2. PROG is displayed. Press Select. Then ON is displayed. (If you do not want to use a schedule, press + or - to display OFF. Press Select.) Press Select.
  3. Press + or - to select day or set of days to edit. Press Select.
  4. Press + or - to select a schedule period to edit (Wake, Away, Home, and Sleep). Press Select.
  5. ON is displayed. Press Select to keep the schedule period on. Or press + and then Select to turn off the schedule period.
  6. Time starts blinking. Press + or - to adjust the schedule period start time. Press Select.
  7. 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 through 7 for the remaining schedule periods.
  9. Press Home when you’re finished to save and return to the home screen.
  10. Schedule can be adjusted and turned ON or OFF by returning to Menu and following the steps provided above.

T4 Schedule program

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Program schedule override (temporary)

  1. Press + or - to adjust the temperature.
  2. Once at the desired setpoint temperature, no further action is needed. The new setpoint temperature will be held until the next scheduled time period begins. For more information on schedule time periods, see “Program Schedule” section.
  3. To cancel the Temporary Hold, Press + or - and then press Cancel.
T4 Temporary Hold

    Program schedule override (permanent)

    1. Press + or - to adjust the temperature.
    2. TEMPORARY HOLD is displayed and the setpoint temperature flashes. While it’s flashing, press Hold (Mode) button to change to Permanent Hold.
    3. To cancel the Permanent Hold, Press + or - and then press Cancel.
    T4 Permanant Hold

     

    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, PART, or ON, and then press Select.
      OFF: Unlocked, and full access allowed.
      PART: Partial lockout, allowing only the temperature to be changed.
      ON: No access allowed.
    4. To unlock the keypad, press the CENTER button and then enter the password “1234”. To enter the password, press + or - to change the first digit of the number. Then press Select. Repeat this process to enter the second through fourth digits of the number. Once all four numbers have been entered, press Select again.
    5. This will unlock the keypad.

    If the code is incorrect, the screen will flash the lines "--".

    Press Back to go back a step to enter the correct number and press Select.

    The default password for all T4 thermostats is "1234"

     

    Battery Replacement

    Batteries are optional (to provide backup power) if your thermostat was wired to run on AC power when installed. If your thermostat was not wired to run on AC power, then batteries are required.
    Install fresh batteries immediately when the low battery icon appears. The icon appears about two months before the batteries are depleted.
    Even if the low battery icon does not appear, you should replace batteries once a year, or before leaving home for more than a month.
    If batteries are inserted within two minutes, the time and day will not have to be reset. All other settings are permanently stored in memory, and do not require battery power.

    T4 Battery IconPNG

    When the low battery warning appears, press gently to loosen the thermostat and then carefully pull it from the wall mount.

    T4 Battery replacement

    Insert fresh alkaline AA batteries.

    T4 Battery cover

    Reinstall thermostat cover.

     

    Alerts T4 alert icon

    If there is an alert or reminder, the alert icon T4 alert icon appears on the Home screen.

    Low Battery Warning

     

    1. The batteries need to be replaced when BATT, the alert icon , and the battery icon are displayed on the Home screen.
    2. When the battery power is very low, the thermostat’s backlight is disabled to save battery power.
    3. When battery power is critically low, only BATT, the alert icon , and the battery icon are displayed.
    T4 Battery alerts

     

    Air Filter Reminder

      1. The alert icon appears on the Home screen.
      2. Press Menu, and then press until display shows ALRT.
      3. Press Select to display which alert(s) are present.
      4. The message REPL (REPLACE AIR FILTER) appears.
      5. The reminder can be snoozed or cleared. Honeywell recommends changing the air filter before clearing the reminder.
      6. To snooze, press Select. The word SNZE (SNOOZE) appears.
      7. Press Select again to snooze the reminder for 7 days.
      8. To clear, press Select, and then press to go to CLER (Clear).
      9. Press Select to clear the air filter reminder.
    T4 air alert

     

     

    Snoozing and Clearing Alerts or Reminders*

    1. Press Menu, and then press until display shows ALRT.
    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, and then press to go to CLER (Clear).
    6. Press Select to clear the reminder.
    T4 clear alerts

     

    * Some alerts cannot be snoozed or cleared. Please call your local heating and cooling professional if this occurs. The heating and cooling system may require service.

    Troubleshooting

    If you have difficulty with your thermostat, please try the following suggestions. Most problems can be corrected quickly and easily.

    Display is blank •Check circuit breaker and reset if necessary.
    •Make sure power switch for heating & cooling system is on.
    •Make sure furnace door is closed securely.
    •Make sure fresh AA alkaline batteries are correctly installed.
    Heating or cooling system does not respond •Press Mode button to set system Heat . Make sure the desired temperature is set higher than the inside temperature.
    •Press Mode button to set system Cool. Make sure the desired temperature is set lower than the inside temperature.
    •Check circuit breaker and reset if necessary.
    •Make sure power switch for heating & cooling system is on.
    •Make sure furnace door is closed securely.
    •Wait 5 minutes for the system to respond.
    Temperature settings do not change • If display says “unlock”; see Adjusting keypack locklout section. If not, verify you are in the correct mode (heat, cool, em heat or auto).
    • If you are in the correct mode, but you cannot set the heat from 40 °F to 90 °F (4.5 °C to 32 °C), or set the cool from 50 °F to 99 °F (10 °C to 37 °C), you may have range-stops restricting your setting. Check with the installer to see if they set range-stops.
    “Cool On” or “Heat On” is flashing •Compressor protection feature is engaged. Wait 5 minutes for the system to restart safely, without damage to the compressor.

    Call Honeywell Customer Care toll-free at 1-800-468-1502.