Picture of the Honeywell RTH9580WF smart thermostat, displaying its -Screen Locked- message.

How to Lock and Unlock a Honeywell Thermostat

Some models of the Honeywell thermostat, including the RTH9580WF we discuss in this post, feature a screen lock mode.  This prevents anyone from changing thermostat settings without first entering a pass code.  You create this code when you lock your thermostat.  Later, the thermostat asks you to enter this password to regain access.  So here we show how to lock and unlock a Honeywell thermostat.  Furthermore, we demonstrate this on Honeywell’s RTH9580WF thermostat. We assume here that your thermostat is fully open (not in lock mode) to start with.

Picture of the Honeywell RTH9580WF Smart Thermostat, front view after initial setup.
Honeywell RTH9580WF smart thermostat, front view after initial setup.

How to Lock and Unlock a Honeywell Thermostat: Locking It

1. Tap the   MENU   Option 

Find the MENU button in top right corner of the screen, which then displays the main menu screen.  Once there, you may have to press the down-arrow button a few times to locate the  Security Settings  item.  The next picture shows the main menu, already scrolled, to reveal this option.

Picture of the thermostat, displaying its main menu, with the -Security Settings- option highlighted.
The thermostat, displaying its main menu, with the -Security Settings- option highlighted.

2. Tap the   Security Settings  Option

The   Security Settings   screen then displays.

Picture of the t-stat, displaying its -Security Settings- screen.
The t-stat, displaying its -Security Settings- screen.

3. Tap the  Change Lock Mode  Button to Continue with How to Lock and Unlock a Honeywell Thermostat

So this brings up the   Change Lock Mode   screen.  Note that the Unlocked option appears in a brighter blue. This means that the thermostat is currently in open mode. Thus, people can access all settings and schedules without unlocking it first. But we are now going to lock it.

Picture of the thermostat, displaying the -Change Lock Mode- screen.
The thermostat, displaying the -Change Lock Mode- screen.

4. Tap the  Fully Locked   Option

This again displays the   Change Lock Mode    screen, but now, shows that  Fully Locked  option highlighted in the bright blue.  The thermostat will go into fully locked mode once you press the   Done   button in the next step.

Note that we could have tapped the   Partially Locked   button here instead. If we had,   that  option would appear in the next screen shot.  But in this demo, we’re only showing what happens with the   Fully Locked   mode.

However, you establish partial locking in the same way as shown below in the Fully Locked case. But the difference is that after locking, you’ll have access to   some   of the thermostat’s settings. These include the current temperature setting on the Home screen. But with full locking, you’ll be able to access  none  of the settings, without first unlocking the thermostat.

Picture of the t-stat, displaying its -Change Lock Mode- screen, with the -Fully Locked- option selected.
The t-stat, displaying its -Change Lock Mode- screen, with the -Fully Locked- option selected.

5. Tap the  Done  Button

This takes you back to the  Security Settings  screen.  Your thermostat is now in full lock.

Note that if you wish not to set up a passcode, you can skip ahead to step 9 below.  The thermostat will still in lock, even with no passcode in effect. So you won’t need a password therefore, to unlock it.  However, here we’re going to add one nonetheless, to demonstrate the comprehensiveness of the locking mechanism on Honeywell thermostats.

Picture of the Honeywell RTH9580WF smart thermostat, displaying its -Security Settings- screen.
Honeywell RTH9580WF smart thermostat, displaying its -Security Settings- screen.

6. Tap the   Create Password   Button to Continue with How to Lock and Unlock a Honeywell Thermostat

The  password-created screen then displays. This shows a four-digit passcode. Now be sure to remember this code, because you’ll need it to unlock the thermostat later.

Picture of the thermostat, displaying its -Your Password has been Created- screen.
The thermostat, displaying its -Your Password has been Created- screen.

7. Write Down the Provided Password

So be careful not to misplace or forget this passcode.  Indeed, record it somewhere and keep it safe.  Without it, you’ll be unable to gain access to the thermostat controls.  Nor will you be able to reset the thermostat to factory defaults without calling Honeywell for help.

8. Press the   Done   Button

Tapping   Done   returns you to the   Security Settings   screen. This shows that the   Create Password   button is now the    Remove  Password   button.

Picture of the t-stat, displaying its -Security Settings- screen, with the -Remove Password- option highlighted.
The t-stat, displaying its -Security Settings- screen, with the -Remove Password- option highlighted.

9.  Tap the   Previous Menu   Button

The  Previous Menu   option returns you to the main menu.

Picture of the t-stat, displaying the -Main Menu- screen, with the -Home- button highlighted.
The t-stat, displaying the -Main Menu- screen, with the -Home- button highlighted.

10.  Tap the   Home   Button to Continue with How to Lock and Unlock a Honeywell Thermostat

Find the Home link in the top left corner of the screen, as arrowed above.   This returns you to the thermostat’s home screen.  The thermostat is now in full lock mode.

Picture of the t-stat, now locked, displaying Its -Home- screen.
The thermostat, now locked, displaying Its -Home- screen.

11. Check that the Honeywell Thermostat Screen is in Lock Mode

Try tapping the up and down arrows that adjust the current temperature setting.  These buttons we circle in pink in the previous picture, at screen right. When the thermostat is in full lock mode, any attempt to change the temperature produces the  Screen Locked   screen.  If you get this page, your RTH9580WF is now in lock mode. Thus you cannot adjust it at all without the passcode.  See below for how to unlock this locked Honeywell smart thermostat.

Picture of the Honeywell RTH9580WF smart thermostat, displaying its -Screen Locked- message.
Honeywell RTH9580WF smart thermostat, displaying its -Screen Locked- message.

12. Press the   OK   Button to Go Back to the   Home   Screen

Note that you may view current thermostat status and settings while locked; you just can’t change anything.

What the Full Lock Mode Restricts on Honeywell 9000 Series Smart Thermostats

Fully locked Honeywell thermostats prevent any changes to settings at all, including the current temperature.

All locked modes (full and partial) disallow the following main menu items.  When locked, these do not appear when you view the thermostat’s main menu.

    • Create Schedule
    • Color Themes
    • Vacation Mode
    • Preferences
    • Temporary Schedule Changes
    • Wi-Fi Setup
    • System Setup

Either lock mode permits access to the following status menu items.

    • View Schedule
    • Weather
    • Equipment Status
    • Clean Screen
    • Security Settings

Partially locked mode disallows the same main menu functions as fully locked mode.  However unlike fully locked mode, partially locked mode allows you to change the thermostat’s current temperature setting.

About the Lock Mode Password

The screen lock mechanism, and Security Settings password feature, function somewhat independently of each other. Yet they are related.  So You may lock the thermostat screen either with or without setting a password. Also you may set a password that fences the Security Settings functions, without actually locking the thermostat screen.

If a password is in effect, you’ll need it to enter the   Security Settings  menu.  Why? Because the password restricts only the access to the   Security Settings   main menu function.

But the lock screen restricts access to certain main menu items as well as the temperature buttons.  These two functions are related in that, to lock or unlock, you need access to the   Security Settings   menu item.  So, if you have set a password, then you’ll need that password to unlock.  If you didn’t set a password, then you won’t need one.

How to Lock and Unlock Unlock a Honeywell Thermostat: Unlocking It

1. On the Home Screen, Tap the  MENU  Option

Firstly, find the   MENU   button in top right corner of that page.

This then displays the main menu screen.  Again, you might have to press the down-arrow multiple times to find the  Security Settings item.

The next picture shows the main menu, already scrolled, to show the   Security Settings   option.

Picture of the thermostat displaying its main menu. Showing the -Security Settings- option.
The thermostat displaying its main menu. Showing the -Security Settings- option.

2. Tap the   Security Settings  Option

A password protected Honeywell thermostat then shows the   Please enter your password   prompt screen.

Picture of the t-stat, displaying its -Please Enter Your Password- screen, with no passcode entered yet.
The t-stat, displaying its -Please Enter Your Password- screen, with no passcode entered yet.

3. Enter the Pass Code to Continue with How to Lock and Unlock a Honeywell Thermostat

Enter the code you assigned when you password-protected the thermostat.  In this demo, our security code was 2752.  So, we tap the UP and DOWN arrows above and below each number position. Thus in this way, we can enter the correct digit for each position.

Again, all that entering this password correctly does, is allow access to the Security Settings menu. This is where you can then either completely unlock, partially lock, or remove the Security Settings password altogether.

Picture of the thermostat, displaying its -Please Enter Your Password- Screen, with passcode 2752 entered.
The thermostat displaying its -Please Enter Your Password- Screen, with pass code 2752 entered.

4.  Press the   Done   Button

Tap   Done   once you’ve punched in the passcode, the thermostat then shows the  Security Settings  screen.

So from here, you could choose either to delete the Security Settings password. Or just choose to change the lock mode while leaving the existing password in effect.  Furthermore, you need not remove the password to unlock the thermostat. Nor must you change the lock mode to remove the password.

Picture of the smart thermostat, displaying its -Security Settings- screen, showing the -Remove Password- button with the -Change Lock Mode- button highlighted.
The smart thermostat, displaying its -Security Settings- screen, showing the -Remove Password- button with the -Change Lock Mode- button highlighted.

5. Tap the  Change Lock Mode   Button

Then the   Change Lock Mode    screen again displays, that shows the  Fully Locked   option highlighted in blue.

Picture of the thermostat displaying its -Security Settings- screen, with the -Unlocked- button highlighted.
The thermostat displaying its -Security Settings- screen, with the -Unlocked- button highlighted.

6. Tap the  Unlocked  Button to Continue with How to Lock and Unlock a Honeywell Thermostat

This unlocks the thermostat and returns you to the  Security Settings  screen.

Picture of the t-stat, displaying its -Security Settings- screen, with the -Previous Menu- button highlighted.
The t-stat, displaying its -Security Settings- screen, with the -Previous Menu- button highlighted.

7. Tap the   Previous Menu   Button

This returns you to the  main menu.  Note that all menu items are now available.  So verify this by scrolling down through them.  If you see that various menu items, then your thermostat is indeed now open.

Picture of the thermostat, displaying the unlocked form of its -Main Menu- screen, scrolled down to show unlocked options.
The thermostat displaying the unlocked form of its -Main Menu- screen, scrolled down to show unlocked options.

8. Done with How to Lock and Unlock a Honeywell Thermostat !

Finally, you are now free to change any setting you wish on the main menu.  Thermostat unlocking is now complete thus.

Other Posts About the Honeywell Thermostat

    1. Honeywell RTH9580WF WiFi Setup Instructions
    2. Change WiFi Network on Honeywell Smart Thermostat RTH9580WF
    3. How to Change Honeywell Thermostat Temperature Setting
    4. Change Time and Day on Honeywell RTH9580WF Thermostat, How To
    5. Connecting Amazon Echo Dot to Honeywell Thermostats

References for How to Lock and Unlock a Honeywell Thermostat

    1. Honeywell Thermostat Official Product Page
    2. Where to Buy a Honeywell Thermostat