Honeywell RTH221B1021/E1 Programmable Thermostat

Owner Manual Thermostat

Installation

1. Turn Off Power to Heating/Cooling System
   
2. Remove Old Thermostat
   
3. Label Wires with Tags
   Label the wires using the supplied wire labels as you disconnect them.
   
4. Separate Wallplate from New Thermostat
   Remove wallplate from the new thermostat and mount onto wall.
   
5. Mount Wallplate
   Mount the new wallplate using the included screws and anchors.
   
   Drill 3/16-in. holes for drywall
   Drill 3/32-in. holes for plaster
6. Connect Wires
   Simply match wire labels.
   If labels do not match letters on the thermostat, check “Alternate Wiring” on page 6 and connect to terminal as shown (see notes, below).
   
   Thermostat does not work on Heat Pumps with auxiliary/backup heat.
   We are here to help. Call 1-800-468-1502 for wiring assistance.
   Alternate Wiring
   
   If wires will be connected to both R and Rc terminals, remove metal jumper.
   Do not use C or X. Wrap bare end of wire with electrical tape.
   If you have a heat pump without auxiliary/backup heat connect O or B, not both. If you do not have a heat pump, do not connect B. Wrap bare end of wire with electrical tape.
   Place a jumper (piece of wire) between Y and W if you are using a heat pump without auxiliary/backup heat.
7. Install Batteries
   
8. Set fan operation switch
   Move the switch to the proper setting:
   Gas or Oil: For gas or oil heating systems, leave the fan operation switch in this factory-set position (for systems that control the fan in a call for heat).
   Electric or Heat Pump: Change the switch to this setting for heat pump or electric heat systems. (This setting is for systems that allow the thermostat to control the fan in a call for heat, if a fan wire is connected to the G terminal.)
9. Install Thermostat onto Wallplate
   Install thermostat onto the wallplate on the wall.
   
10. Turn Power Back On
    Turn the power back on to the heating/cooling system.
    
11. If your system type is...
    If your system type is:
    Single Stage Heat and Cool
    Heat Only or Cool Only
    Congratulations, you’re done!
    If your system type is:
    Heat pump
    High efficiency furnace
    Hot water
    Electric furnace
    Gas/oil steam
    Gravity system
    Continue with Advanced Installation to match your thermostat to your system type.

Advanced Installation

Enter System Setup

To enter system setup, press and hold both the and buttons until the display changes (approximately 5 seconds).

Changing Settings

1. Press the or button to change the setting.
2. Press the and buttons simultaneously for one second to advance to the next function.
3. Press the RUN button to exit and save settings.

NOTE: If you do not press any button for 60 seconds while you are in the setup menu, the thermostat automatically saves any changes made and exits the menu.

* Compressor Protection: This feature forces the compressor to wait approximately 5 minutes before restarting, to prevent equipment damage. During the wait time, the message “Cool On” or “Heat On” is displayed on screen.

About your new thermostat

Your new Honeywell thermostat has been designed to give you many years of reliable service and easy-to-use, push-button climate control.

• Backlit display on RTHL2310
• Displays ambient (measured) temperature at all times
• One-touch access to setpoint temperature
• Preset program settings
• Temporary and permanent override of schedule
• Built-in compressor protection

Thermostat controls

Display screen

Set the time and day

1. Press the SET button, then press or to set the clock time.
2. Press the SET button, then press or to select the day of the week.
3. Press RUN to save & exit.

NOTE: If the clock flashes, the thermostat will follow your settings for the Monday “Wake” time period until you reset the time and day.

Program Schedule

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

Wake - Set to the time you awaken and the temperature you want during the morning, until you leave for the day.

Leave - Set to the time you leave home and the temperature you want while you are away (usually an energy-saving level).

Return - 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).

NOTE: Leave and Return periods can be canceled on weekends.

To adjust program schedules (RTHL221)

1. Press SET until Set Schedule is displayed.
2. Press or to set your Wake time (Mo-Su), then press SET.
3. Press ​​​​​​​ or to set the temperature for this time period, then press SET.
4. Set time and temperature for the next time period (Leave). Repeat steps 2 and 3 for each time period.
5. Press RUN to save & exit.

NOTE: Make sure the thermostat is set to the system you want to program (Heat or Cool).

Program schedule override (temporary)

Press ​​​​​​​ or ​​​​​​​ to immediately adjust the temperature. This will temporarily override the temperature setting for the current time period.

“Temporary” will appear on the display and the current program period will flash.

The new temperature will be maintained only until the next programmed time period begins (see page 11).

To cancel the temporary setting at any time, press RUN.

NOTE: Make sure the thermostat is set to the system you want to control (heat or cool).

Program schedule override (permanent)

Press HOLD to permanently adjust the temperature. This will override the temperature settings for all time periods.

The “Hold” feature turns off the program schedule and allows you to adjust the thermostat manually, as needed.

Whatever temperature you set will be maintained 24 hours a day, until you manually change it, or press RUN to cancel “Hold” and resume the program schedule.

NOTE: Make sure the thermostat is set to the system you want to control (heat or cool).

Built-in compressor protection

This feature helps prevent damage to the compressor in your air conditioning or heat pump system.

Damage can occur if the compressor is restarted too soon after shutdown. This feature forces the compressor to wait 5 minutes before restarting.

Battery replacement

Install two fresh AAA batteries when Lo Batt flashes on the screen. Lo Batt appears for 60 days before the batteries are depleted.

Replace batteries once a year, or when you will be away for more than a month.

Most settings are stored in non-volatile (permanent) memory. Only the clock and the day must be set after you replace the batteries.

WARNING: Set the System switch to Off before removing the batteries. Otherwise, the heating/cooling system could remain activated even when batteries are removed.

Troubleshooting

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

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