Honeywell RTH2300 Thermostat User Guide

Honeywell RTH2300 Thermostat


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To prevent possible compressor damage, do not use Cooling mode when the outdoor temperature is below 50°F (10°C).

Need Help?
For assistance with this product please visit or call Honeywell Customer Care toll-free at 1-800-468-1502.

Read and save these instructions.

About your new thermostat

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


  • Backlit display is easy to read
  • Displays ambient (measured) temperature at all times
  • One-touch access to setpoint temperature
  • Energy-saving settings for maximum cost savings
  • Separate programmable weekday/weekend schedules (5+2 day programming)
  • Temporary and permanent override of schedule
  • Built-in compressor protection

Quick reference to controls

FIG 3 Quick reference to controls

Quick reference to display

FIG 4 Quick reference to display

Set the clock

FIG 5 Set the clock
  • Press the Set button. Set Time will appear on the screen and the time display will flash.
  • Press the Up or Down button to set the time.
  •  Press the Set button again. Set Day will flash on the screen.
  •  Press the Up or Down button to select the day of the week.
  • Press the Run button to save the changes & exit. (The changes are also saved if you do not press any button for 60 seconds.)

NOTE: The clock has lost its settings when the time display flashes. If the thermostat is following the schedule, it will use the temperature settings programmed for the Wake period of the weekdays until you readjust the clock.

System switch (Heat/Cool)

FIG 6 System switch (Heat or Cool)

Use the System switch to place the system in one of the following modes:

  • Cool: System is in Cooling mode.
  •  Off: System is off.
  • Heat: System is in Heating mode.

Do not use Cooling mode when the outdoor temperature is below 50°F (10°C).

Fan switch (Auto/On)

FIG 7 Fan switch (Auto or On)

Use the Fan switch to select the fan operation.

  • Auto: The fan runs only when heating or cooling is activated (commonly used setting).
  • On: The fan runs continuously.

Using the schedule

Press the Run button to follow the programmed schedule. For maximum energy savings while maintaining comfort, you can program the schedule such that the temperature is at an economical level when you sleep or leave for work and at a comfortable level when you are awake and at home. You can program up to four periods per day:

FIG 8 Using the schedule

To program a period, you need to set its start time and its two temperature settings (one when the thermostat is in cooling mode and another one when it is in heating mode). The same settings are used every day from Monday to Friday and another set of settings are used for Saturday and Sunday. For example, you could program all four periods for the weekdays but only two periods (Wake and Sleep) for the weekends.

Energy saving default schedule

This thermostat is pre-set with energy-saving program settings. See the next page if you wish to modify the settings.

FIG 9 Energy saving default schedule

Modifying the schedule

FIG 10 Modifying the schedule
  • Press the Set button 3 times until Set Schedule appears. The Wake period is displayed.
    NOTE: To set another period, press the Set button as many times as needed until the desired period and the desired days are displayed and its time or temperature is flashing.
  • When the time flashes, press the Up or Down button to set the time.
  •  Press the Set button.
  •  To set the temperature for cooling mode, first place the System switch in Cool. To set the temperature for heating mode, first place the System switch in Heat.
  • When the temperature flashes, press the Up or Down button to set the temperature.
  •  Press the Set button.
  •  Repeat steps 2 through 6 to set each of the remaining periods.
  •  Once all changes are made, press the Run button to save them and return to normal display. (The changes will automatically be saved if you do not press any button for 60 seconds.)

Temporary override of schedule

FIG 11 Temporary override of schedule

To temporarily ignore the schedule, press the Up or  Down button until the desired temperature is displayed.  The word Temporary will appear on the screen and the period display will flash to indicate that the current period has been overridden. The new temperature will be used until the next period begins.

NOTE: Pressing the Up or Down button once will display the setpoint temperature. To change the setpoint temperature, press either button more than once.

Press the Run button if you wish to cancel the temporary setting before the beginning of the next period.

Permanent override of schedule

To permanently ignore the schedule, press the Up or Down button until the desired temperature is displayed. Then, press the Hold button to maintain the new temperature indefinitely. The word Hold will appear on the screen.

FIG 12 Permanent override of schedule

Press the Run button if you wish to cancel the override and resume the schedule. The word Hold will disappear and the thermostat will be set to the temperature programmed for the current period.

Built-in compressor protection

Your thermostat has a feature that helps prevent damage to the compressor of your air conditioning or heat pump system. Because 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 message Cool On or Heat On flashes on the screen. When the safe wait time has elapsed, the message stops flashing and the compressor turns on.

Battery replacement


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

FIG 13 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.

In case of difficulty

FIG 14 In case of difficulty

Customer assistance

For assistance with this product, please visit Or call Honeywell Customer Care toll-free at 1-800-468-1502.

To save time, before calling, proceed as follows:

FIG 15 Customer assistance
  1. Loosen the locking screw at the bottom of the thermostat. Note that the screw is captive and cannot be removed from the wall plate.
  2. Separate the thermostat from the wall plate as per figure on the right.
  3. Note your model number and date code on the thermostat’s wall plate.

One-year limited warranty

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

  •  return it, with a bill of sale or other dated proof of purchase, to the place from which you purchased it; or
  • call Honeywell Customer Care at 1-800-468-1502. Customer Care will make the determination whether the product should be returned to the following address: Honeywell Return Goods, Dock 4 MN10-3860, 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 Honeywell that the defect or malfunction was caused by damage which occurred while the product was in the possession of a consumer.

Honeywell’s sole responsibility shall be to repair or replace the product within the terms stated above. HONEYWELL 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.


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 to Honeywell Customer Relations, 1985 Douglas Dr, Golden Valley, MN 55422 or call 1-800-468-1502. In Canada, write to Retail Products ON15-02H, Honeywell Limited/Honeywell Limitée, 35 Dynamic Drive, Toronto, Ontario M1V 4Z9.

Automation and Control Solutions
Honeywell International Inc.
1985 Douglas Drive North
Golden Valley, MN 55422
Honeywell Limited
35 Dynamic Drive
Toronto, Ontario M1V 4Z9
© 2011 Honeywell International Inc.
Printed in U.S.A.
69-2326ES-04 M.S. Rev. 03-11

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Read More About This Manual & Download PDF:

Documents / Resources

Honeywell RTH2300 Thermostat [pdf] User Guide
RTH2300, Thermostat, 69-2326ES, 69-2326ES-04

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