Honeywell Home Programmable Thermostat

Read Before Installing

For help, please visit resideo.com.

Identify System Type

This thermostat is compatible with the following systems:

• Gas, oil or electric furnace
• Central air conditioner
• Hot water system with or without pump
• Millivolt system
• Central heating and cooling system
• Heat pump without auxiliary/backup heat

Do you need assistance? We are here to help.

Call 1-800-468-1502 for wiring assistance before returning the thermostat to the store.

This thermostat cannot be used on heat pumps with backup heat or on multistage systems.

Input: 2 x AAA batteries (1.5V each)

ATTENTION: MERCURY RECYCLING NOTICE

[Mercury Symbol] NO MERCURY NE PAS JETER LE MERCURE

This product does not contain mercury. However, this product may replace a product that contains mercury. Mercury and products containing mercury should not be discarded in household trash.

For more information on how and where to properly recycle a thermostat containing mercury in the United States, please refer to the Thermostat Recycling Corporation at www.thermostat-recycle.org.

For mercury thermostat recycling in Canada, please refer to Switch the Stat at www.switchthestat.ca.

NOTICE: Compressor Protection

⚠️ To avoid possible compressor damage, do not run air conditioner if the outside temperature drops below 50°F (10°C).

Customer Assistance

For assistance with this product, please visit resideo.com.

Or call Resideo Customer Care toll-free at 1-800-468-1502.

To save time, please note your model number and date code before calling.

To remove the thermostat from the wallplate, pull at the bottom.

Turn the thermostat over to find the model number and date code.

Installation

1 Turn Off Power to Heating/Cooling System

Before starting installation, turn off power to your heating and cooling system. This is typically done at the circuit breaker box or a dedicated power switch for the system.

2 Remove Old Thermostat

Remove the old thermostat, but leave the wallplate with wires attached. Do not remove the wallplate yet.

⚠️ If you have an older thermostat with a sealed mercury tube, follow specific disposal instructions (refer to page 2 of the original document).

Terminal Designation: The diagram shows common terminal designations on older thermostats, such as R, W, Y, G, C, and others.

3 Label Wires with Tags

As you disconnect each wire from the old thermostat, label it using the supplied wire labels that correspond to the terminal designation (e.g., R, W, Y, G, C, B, etc.).

Wire Labels Diagram: Shows a chart matching wire labels to terminal designations for various systems.

4 Separate Wallplate from New Thermostat

Remove the wallplate from the new thermostat. This wallplate will be mounted to the wall.

Wallplate Diagram: Shows the new thermostat's wallplate with mounting holes and a label indicating where to pull to separate it from the thermostat body.

5 Mount Wallplate

Mount the new wallplate to the wall using the included screws and anchors. If your wall anchors are red, drill 7/32" (5.6 mm) holes. If they are yellow, drill 3/16" (4.8 mm) holes.

6 Connect Wires

Simply match the wire labels to the corresponding terminals on the new wallplate. If labels do not match the letters on the thermostat, refer to the "Alternate Wiring" section on page 6.

Wire Connection Diagram: Illustrates inserting labeled wires into the terminal block (B, O, G, Y, W, Not Used, R, Rc). It also notes to remove the metal jumper if you have both R and Rc wires.

Note: This thermostat does not work on heat pumps with auxiliary/backup heat.

For wiring assistance, call 1-800-468-1502.

7 Install Batteries

Install two AAA alkaline batteries into the back of the thermostat.

8 Set fan operation switch

Move the internal fan operation switch to the correct setting:

• Gas or Oil: Leave the switch in the factory-set position for systems that control the fan during a heat call.
• Electric or Heat Pump: Change the switch to this setting for heat pump or electric heat systems, allowing the thermostat to control the fan if a wire is connected to the G terminal.

9 Install Thermostat onto Wallplate

Attach the thermostat body to the mounted wallplate.

10 Turn Power Back On

Restore power to your heating/cooling system at the circuit breaker box or power switch.

Advanced Installation

11 If your system type is...

Select your system type:

• [ ] 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.

If you are unsure of your system type or have other questions, call 1-800-468-1502.

This thermostat works on 24 volt or 750 mV systems. It will NOT work on multistage conventional systems.

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: Auto-save

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

Configuration Settings

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

• Backlit display on RTH2300
• 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

Programming and Operation

Thermostat controls

Set: Press this button to set the time/day/schedule.

Hold: Press this button to override programmed temperature control.

Run: Press this button to resume the program schedule.

System Switch: This switch is used to control your heating or cooling system.

• Heat: Heating system control.
• Off: All systems off.
• Cool: Cooling system control.

Temperature adjustment: Press the up or down buttons until you reach the desired temperature.

Note: Make sure the SYSTEM switch is set to the system you want to control (Heat or Cool).

Fan Switch: This switch is used to control your fan. In "Auto" mode, the fan runs only when the heating or cooling system is on. If set to "On,” the fan runs continuously.

Display screen

Setpoint indicator: Appears when the setpoint temperature is displayed.

Current day/time: (see page 11)

Current program period: Wake/Leave/Return/Sleep (see pages 11-13)

System status:

• Cool on: Cooling system is on.
• Heat on: Heating system is on.
• When Cool On is flashing, compressor protection is engaged (see page 14).

Low battery warning: (see page 14)

Temperature: The ambient (measured) temperature is normally displayed. To view the setpoint temperature, press the Up or Down button once. The setpoint temperature will appear for five seconds.

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 (RTH2300)

1. Press SET until Set Schedule is displayed.
2. Press ▲ or ▼ to set your weekday Wake time (Mo-Fr), 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 weekday time period.
5. Press SET to set weekend time periods (Sa & Su), then press RUN to save & exit.

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

To adjust program schedules (RTH221)

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.

During the wait time, the display will flash the message Cool On (or Heat On if you have a heat pump). When the safe wait time has elapsed, the message stops flashing and the compressor turns on.

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.

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

To remove the thermostat from the wallplate, pull from the bottom.

Turn the thermostat over, insert fresh AAA alkaline batteries, then reinstall the thermostat.

Appendices

Troubleshooting

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

For assistance with this product, please visit resideo.com or call Resideo Customer Care toll-free at 1-800-468-1502.

1-year limited warranty

Resideo warrants this product, excluding battery, to be free from defects in workmanship or materials, under normal use and service, for a period of one (1) year from the date of first purchase by the original purchaser. If at any time during the warranty period the product is determined to be defective due to workmanship or materials, Resideo shall repair or replace it (at Resideo's option).

If the product is defective:

1. Return it, with a bill of sale or other dated proof of purchase, to the place from which you purchased it; or
2. Call Resideo Customer Care at 1-800-468-1502. Customer Care will make the determination whether the product should be returned to the following address: Resideo Return Goods, 1985 Douglas Dr. N., Golden Valley, MN 55422, or whether a replacement product can be sent to you.

This warranty does not cover removal or reinstallation costs. This warranty shall not apply if it is shown by Resideo that the defect was caused by damage which occurred while the product was in the possession of a consumer.

Resideo's sole responsibility shall be to repair or replace the product within the terms stated above. RESIDEO SHALL NOT BE LIABLE FOR ANY LOSS OR DAMAGE OF ANY KIND, INCLUDING ANY INCIDENTAL OR CONSEQUENTIAL DAMAGES RESULTING, DIRECTLY OR INDIRECTLY, FROM ANY BREACH OF ANY WARRANTY, EXPRESS OR IMPLIED, OR ANY OTHER FAILURE OF THIS PRODUCT.

Some states do not allow the exclusion or limitation of incidental or consequential damages, so this limitation may not apply to you.

THIS WARRANTY IS THE ONLY EXPRESS WARRANTY RESIDEO MAKES ON THIS PRODUCT. THE DURATION OF ANY IMPLIED WARRANTIES, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, IS HEREBY LIMITED TO THE ONE YEAR DURATION OF THIS WARRANTY. Some states do not allow limitations on how long an implied warranty lasts, so the above limitation may not apply to you.

This warranty gives you specific legal rights, and you may have other rights which vary from state to state. If you have any questions concerning this warranty, please write Resideo Customer Care, 1985 Douglas Dr, Golden Valley, MN 55422 or call 1-800-468-1502.

Resideo Technologies Inc.
1985 Douglas Drive North, Golden Valley, MN 55422
1-800-468-1502
33-00100EF-03 M.S. Rev. 02-20 | Printed in United States

©2020 Resideo Technologies, Inc. All rights reserved. The Honeywell Home trademark is used under license from Honeywell International, Inc. This product is manufactured by Resideo Technologies, Inc. and its affiliates.