How To Unlock Honeywell Thermostat Complete Guide
Have you recently tried to lock and unlock your Honeywell Thermostat? In this article, I will discuss how to unlock Honeywell Thermostats quickly for most of the models present on the market.
I recently got a Honeywell Thermostat [1] installed in my house. And since my kids started growing up they always mess around with the electronic products present in my house.
A few days ago, someone used a chair to get to the thermostat. They were able to change the temperature level on my thermostat with this method. As a result, there was a warm temperature all over the house that I didn’t like. To make sure that my kids didn’t change the temperature again, I looked into how to lock and unlock the Honeywell thermostat.
Most of the time, you need to enter the PIN when the Thermostat asks if you want to unlock the page. Honeywell makes a lot of different kinds of thermostats, and we’ll see in the guide below how you can lock or unlock them.
How To Unlock T4 Pro Series Thermostat
First I am going to discuss how to unlock the T4 Pro Series Honeywell Thermostat. To Unlock the T4 Pro series follow the below steps properly one after another. Before following the below steps make sure that the screen lock is active. You will be able to see the Lock icon on the Screen.

There are three different locking options available on your Honeywell thermostat. The “Full” locking setting prevents you from entering the keypad, while the “Partial” locking setting allows you to adjust the temperature, and the “Off” setting allows the device to remain in the unlocked position at all times.
- Select Menu Button on the Thermostat that is present in the Center.
- Press + or – button to proceed to LOCK options and then press Select Button.
- Press + or – button to see options OFF, PART, or ON and then press the Select Button.
- Once you’ve pressed the center button and entered the password “1234”, the keypad will be unlocked. To alter the initial digit of the password, hit + or -. Then, press Select. Re-enter each digit of the number using this procedure. Press Select again after you’ve input all four numbers.
- Now using this method the Keypad will get Unlocked.
- If you will enter the code incorrectly you can see the screen flashing “–“.
- Then you can press Back button and then you can try re-entering the unlock code.
Using the above steps you will be able to unlock your T4 Pro Series Thermostat easily.
How To Unlock T6 Pro Series Thermostat
If you are using the T6 Pro Series Thermostat and you have completed the steps to lock the Thermostat then you can use the below steps to unlock the Thermostat.
- Make sure that Lock Icon is displayed on the Screen indicating that the Thermostat is currently in Locked state.
- Press Lock Sign on the Screen.
- Now you will be asked to enter the PIN number that you entered to Lock the Screen.
- You need to use the + or – sign to input the Digits that you entered to Lock it.
- Once you have selected the input Digit to confirm that Digit Press Select.
- Keep repeating the above step to complete the entering of Four Digit Number.
If you are facing the issues related to unlocking the T6 Pro series if you are trying to enter the code as 1234 initially. Then for T6 Pro, the code is 1234 + the date code. To find the date code you need to look on the top right of the base.
Once you have found your date code adds that with 1234 and then enter the final number to the screen as a PIN. For example, if the date code is 1635 then add 1234 to it and your code will be 2869.
How To Unlock Honeywell 8000 Series Thermostat
If you are having the Honeywell 8000 Series thermostat such as RTH8500 WiFi Series or TH8000 installed in your house then you can follow the below steps to get the thermostat unlocked.
- Using two fingers on your display, press and hold the System and Auto buttons together.
- Hold down the blank lower center button for a few seconds until the screen changes. Hold the 2nd and 4th blank buttons down on various models to activate the camera.
- Using the up and down arrows in the middle of the display, change the left values to 0670.
- Using the up/down arrows on the right, change the right value to zero.
- To confirm, press the DONE button on the lower right.
Using the above steps you may now be able to unlock the RTH8500 Wi-Fi Series or TH8000 Series Honeywell Thermostats easily.

Types Of Lock Modes In Honeywell Thermostat
Honeywell thermostats are locked for a variety of reasons, the most important of which is so that we can manage who has access to the settings of our devices.
In order to secure the keypad of our devices, we can choose between a ‘Full’ lock and a ‘Partial’ lock. When you go to the ‘Menu’ portion of your smartphone, you will be able to view this choice.

Your Honeywell thermostats have three different lock settings for you to choose from.
It is indicated by the names in brackets how they will be shown on the device.
Full (On): The ‘Full’ lock setting limits access to the thermostat’s settings on the entire computer system.
Partial (Part) lock: The ‘Partial’ lock setting will allow you to adjust the temperature. There will be no access to any other settings.
Locked (Off): When you select this lockset, the keypad of your thermostat will be unlocked.
PINs can be used to disable the ‘On’ and ‘Part’ locking settings. If you have a tendency to wander from your timetable, keep the locking option set to ‘Part’ for now. Make sure your device’s lock is set to “Full” if you leave it to work on a regular basis.
You’ll save valuable time this way! You should, however, take care not to lose track of your lock code. When the lock code is entered, the lock mode is disabled, and the system is switched to the ‘Off’ option, which is the default setting.
The unlocking technique for your Honeywell thermostats can be easily learned by following the steps outlined below.
How To Unlock Honeywell Thermostat Without Code
If you have forgotten your unlock code for Honeywell thermostat T4 or T6 then it can still be unlocked but it is different from what is being informed above.
Usually, you will forget your passcode if you are not using it frequently. And this can be frustrating when you are trying to remember and you cannot. So in this case you should know how to unlock the Honeywell thermostat without code.

Or Your kids may have modified your device’s lock configuration and the previous one that you remember is not working anymore. The PIN for the T4 Pro is normally 1234.
To unlock a Honeywell Pro series thermostat without a pin:
- Remove the faceplate and look for a four-digit number in the upper right corner.
- Once you have noted down the Twelve-digit code add 1234 in the end.
- The result of the sum will be your thermostat’s PIN.
- To unlock your device using the new PIN mentioned in this section, simply follow the previous procedures.
Wrap Up
I hope you were able to unlock your Thermostat using the above Method discussed for various thermostat models available and widely used in the Market. As you know there are three modes that you can select on any thermostat.
If you want to keep the temperature constant, you can set either a Temporary Hold or a Permanent Hold. This will ensure that you will never have to deal with the inconvenience of having the thermostat settings modified by unsuspecting children or guests again.
Following the completion of your thermostat configuration to your satisfaction, you may take advantage of the additional cool features offered by your Honeywell Thermostat, such as the automatic scheduling feature.
Please let me know in the comment section if you have any better methods than the ones discussed above I will be happy to add those here.
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