6 min read • Updated October 2026 • By the CliQ Team — the team that created Blink
How do you reset a Honeywell thermostat? First decide which reset you need. For a frozen or glitchy screen, a restart is enough: set the System to Off, pull the thermostat off its wall plate, take the batteries out for a minute, and put everything back. Your settings survive. To wipe the schedule or start over completely, use your model's menu (steps by model below). There's no reset button on any of the models covered here.
A full factory reset also wipes the installer settings that match the thermostat to your heating and cooling system. Do that one only when you mean it.
Which Reset Do You Need?
| The problem | The reset | What it erases |
|---|---|---|
| Screen frozen, blank, or acting strange | Restart | Nothing, though the clock may need setting |
| Schedule is a mess and you want to start fresh | Schedule reset | Your schedule (it goes back to Honeywell's defaults) |
| Bought it used, moved into a new home, or setup went wrong | Factory reset | Everything, including installer settings for your system type |
| Keypad says "Locked" | No reset needed | Nothing. On T4 Pro and T6 Pro models, press the center button and enter 1234 |
| "Cool On" flashing after any of the above | No reset needed | Nothing. It's a 5-minute compressor delay, so wait it out |
How to Restart a Honeywell Thermostat (Any Model)
- Set the System to Off.
- Pull the thermostat straight off its wall plate. Pull gently. The pins on the back bend easily.
- Take the batteries out for about a minute, then put them back. Use fresh ones if they're old.
- Press it back onto the wall plate and set the System back to Heat or Cool.
- Check the time and day.
This is safe. Honeywell's T4 Pro and RTH manuals both say your settings are stored in permanent memory that doesn't need battery power. At most, the clock resets. On the T4 Pro, even the clock is kept if the batteries go back in within two minutes.
If your thermostat has no batteries and runs on house power, restart it by switching off the breaker for the furnace or air handler for a minute instead. Honeywell's troubleshooting list for a blank screen starts there anyway: check the circuit breaker, the system's power switch, and the furnace door.
After any restart, give it five minutes. Honeywell thermostats hold the air conditioner or heat pump compressor for about five minutes after power returns. "Cool On" flashes during the wait. That's protection, not a problem.
How to Reset the Schedule
Want to keep everything else and just start the schedule over? These steps come from Honeywell's manuals and support site:
- RTH2300: press and hold the up and down buttons together for about five seconds to open system setup. Press both together for one second at a time to step through the functions until you reach function 40. Press up to set it to 1, then press Run to save and exit. Function 40 is RTH2300-only.
- T5, T5+, and T6 Wi-Fi (RCHT8610WF, RCHT8612WF, TH6220WF2, TH6320WF2): press and hold Menu, scroll to Reset, then select Schedule.
- FocusPRO 6000 Wi-Fi (TH6320WF1, RTH6580WF): press and hold the up arrow and Fan. Set the number on the left to 85 and the number on the right to 1, then press Done.
- Smart WiFi 9000 (RTH9580WF, RTH9585WF, TH9320WF): press Menu, then Preferences, then Restore Default Schedule.
- VisionPRO 8000 (TH8320WF, RTH8580WF): press System, then press and hold the blank box in the center. Set the left number to 0165 and the right number to 1, then press Done.
- T4 Pro: Honeywell's guides don't list a schedule-only reset. Edit the schedule directly instead: press Menu, then PROG.
Then set a schedule worth keeping. The US Department of Energy says setting the thermostat back 7–10°F for 8 hours a day can save up to 10% a year on heating and cooling. Our guide to programming any thermostat walks through picking the times and temperatures.
How to Factory Reset a Honeywell Thermostat, by Model
Before you factory reset, take a photo of the installer settings. These settings tell the thermostat what kind of system you have: gas furnace or heat pump, how many stages, and more. A factory reset puts them all back to the defaults, which may not match your home. If you're not sure how to set them again, stop here and call an HVAC technician, or the Customer Care number in Honeywell's manuals, 1-800-468-1502.
| Model | Factory reset steps |
|---|---|
| T4 Pro (TH4110U, TH4210U) | Press and hold Menu and + for about 5 seconds to open the advanced menu. Press + until RESET appears, then press Select. (This step is shown on the thermostat in the video below. Honeywell's printed guides don't list it.) |
| RTH2300 / RTH221 | Honeywell's manual has no full factory reset. Use function 40 to restore the schedule (RTH2300), and change installer settings one at a time in the same setup menu. |
| T5, T5+, T6 Wi-Fi | Press and hold Menu. Scroll to Reset and select it, then select Factory Reset. |
| FocusPRO 6000 Wi-Fi (TH6320WF1, RTH6580WF) | Press and hold the up arrow and Fan. Set the left number to 90 and the right number to 1. Press Done. |
| Smart WiFi 9000 (RTH9580WF, RTH9585WF, TH9320WF) | Press Menu, then Preferences, then Restore Factory Defaults. Select Yes. |
| VisionPRO 8000 (TH8320WF, RTH8580WF) | Press System, then press and hold the blank box in the center. Set the left number to 0710 and the right number to 1. Press Done. |
| T9 (RCHT9510WF, RCHT9610WF) | Press Menu, then Advanced Setup, then Reset, then Factory Reset. |
Video by Hotrods & Homestead via YouTube, July 2023. Not affiliated with CliQ.
On a T4 Pro (TH4110U2005), he holds Menu and +, scrolls past ISU to RESET, and presses Select. Every setting goes back to factory condition. His warning is the important part: if you bought the thermostat used, or it came with the house, set it up again for your own heating and cooling system afterward.
Not on the list? Find the model number on the sticker on the back of the thermostat, then search "Honeywell [model] manual." A round dial or a model with no screen has no memory, so there's nothing to reset.
Not sure a reset is the fix? Our Honeywell troubleshooting guide works through every common symptom first.
Thinking about replacing your thermostat instead?
See the CliQ Smart Thermostat →Frequently Asked Questions
How do I reset my Honeywell thermostat?
For most problems, restart it: set the System to Off, pull the thermostat off the wall plate, remove the batteries for a minute, and put it back. Your settings are kept. To reset the schedule or do a full factory reset, use your model's menu. The steps differ by model.
How do I reset a Honeywell thermostat with no reset button?
The Honeywell models covered here reset through button combinations or menus, not a dedicated button. On a T4 Pro, hold Menu and + for about five seconds. On an RTH2300, hold the up and down buttons together. On T5 and T6 Wi-Fi models, press and hold Menu.
Will resetting my Honeywell thermostat erase my schedule?
A restart won't. Honeywell's T4 Pro and RTH manuals say settings are stored in permanent memory. A schedule reset or factory reset will. A factory reset also erases the installer settings for your system type, so you may need to set those up again.
How do I factory reset a Honeywell T4 Pro?
Press and hold Menu and + for about five seconds to open the advanced menu, press + until RESET appears, and press Select. Take a photo of your installer (ISU) settings first, because the reset returns them to the defaults.
How do I reset the Wi-Fi on a Honeywell thermostat?
It depends on the model. On T5, T5+, and T6 Wi-Fi models, press and hold Menu, scroll to Reset, and select WiFi. On a FocusPRO 6000 Wi-Fi, hold the up arrow and Fan, set the left number to 39 and the right to 0, and press Done. On a Smart WiFi 9000, press Menu, then WiFi Setup.
I reset my thermostat and the AC won't start. Is it broken?
Probably not. After a restart, Honeywell thermostats make the compressor wait about five minutes, and "Cool On" flashes during the wait. If you did a factory reset, also check that the installer settings match your system. A heat pump set up as a gas furnace, for example, may not run correctly.
Sources
Honeywell Home — How do I reset my Honeywell Home device? — honeywellhome.com
Honeywell Home — How do I access the installer setup (ISU) on my TH4210U2002, TH4110U2005 thermostat? — honeywellhome.com
Resideo — T4 Pro Programmable Thermostat Installation Instructions (33-00187EFS-17, 2022) — resideo.com
Resideo — T4 Pro Programmable Thermostat User Guide (33-00188EFS-11, 2022) — PDF
Resideo — Programmable RTH2300/RTH221 Thermostat Series Owner's Manual — PDF
US Department of Energy — Programmable Thermostats — energy.gov
Photo by Erik Mclean via Pexels
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