How to Lock and Unlock Honeywell Pro Series Thermostats

Own a Honeywell Pro Thermostat and want to lock or unlock it? Here is the guide on how to lock and unlock Honeywell Pro Series Thermostat.

Thermostats are essential devices in every household when it comes to heating or cooling your home. One of the popular thermostat brands is Honeywell. Honeywell makes a large number of thermostats that you can purchase for your home. You can choose between the programmable and non-programmable ones. Or, you can go for the Pro or non-pro series. Either one lets you control and manage the temperatures in your home.

With thermostats installed in your homes, it is vital to ensure that the settings and schedules that have been set up have not been interfered with. There will always be someone who wants to keep changing temperatures or maybe the kid who wishes to play with temperatures all the time. In this case, locking up the thermostat is a better idea. In this guide, we will be talking about how you can lock as well as unlock the thermostats easily. Let’s get started.

How to Lock Honeywell Pro Series Thermostats

Whether you want to lock your settings to the thermostats or want to unlock them to change the settings, you can easily perform both tasks without having to struggle around too much.

Lock Honeywell T4 Pro Series Thermostats

Locking the Honeywell Pro series thermostats is simple and easy. You can follow these steps that will work with the Honeywell T4 Pro Series Thermostats.

How to lock Honeywell Pro Series Thermostats
  1. First, press the Menu button on your thermostat.
  2. Now, use the Plus or Minus buttons on the thermostat to navigate through the menus.
  3. Once you get the Lock option on your screen, Select it by pressing the Select button on your thermostat.

Lock Honeywell T6 Pro Series Thermostat

If you own a T6 Pro series thermostat, you can easily lock it but with a different method. Here is how:

  1. Tap on the Menu option and navigate through the menu.
  2. Select the Screen Lock options.
  3. Tapping on select will let you choose between Full Lock or Partial Lock. Choose the one that you prefer.
  4. The PIN will be displayed when you select either option. Make sure to take note of this PIN as it will be needed to unlock the thermostat.

How to Unlock Honeywell Pro Series Thermostats

After locking the thermostat you will also need to unlock it when you want to change its settings. And so here is the guide to unlock Honeywell Pro series thermostats.

Unlock Honeywell T4 Pro Series Thermostats

Locked your Honeywell T4 Pro series thermostat and now want to unlock it? Here’s how you can unlock the very same thermostats. Follow these steps.

  1. Press the Center button on your thermostat and enter the password.
  2. The default password is 1 2 3 4.
  3. You can use the + or – buttons on your thermostat to select the digits for your password.
  4. Now repeat the process three more times in order to successfully enter the password.
  5. Once the password has been entered, the keypad for the thermostat has been unlocked. You can now change the settings and adjustments for the T4 Pro Series thermostats.

Unlock Honeywell T6 Pro Series Thermostat

If you know the PIN that was displayed when locking the T6 Pro series thermostat, you can enter it to unlock the same thermostat.

How to Unlock Honeywell Pro Series Thermostats
  1. Tap on the lock icon displayed on the screen of the T6 pro.
  2. Now, enter the PIN code.
  3. Your T6 Pro Series thermostat has been unlocked.

How to Unlock Honeywell Pro Series Thermostat if you forgot its PIN

In case you have forgotten the PIN for your T6 Pro Series, you can still unlock it. Here are the steps that you need to carefully follow to unlock the thermostat.

  1. First, remove the T6 Pro series thermostat from the wall.
  2. Remove the back plate from the thermostat.
  3. At the back, you should be seeing some text. Ans at the top right corner, you will find 4 digits.
  4. Note the digits printed and add them to 1234.
  5. The sum of 1234 and the printed digits will be the PIN for your T6 pro series thermostat.
  6. Once you have noted it down, connect the thermostat back to the wall and tap the lock icon.
  7. Now, enter the PIN from the sum of both numbers.
  8. Your T6 Pro Series thermostat has now been unlocked.


This is how you can lock as well as unlock Honeywell T4 Pro and T6 Pro series thermostats. Having these devices locked is always good as it helps to regulate the temperatures in your house without it constantly changing all the time. Plus, it prevents kids from messing with the settings. In case you have any issues with your thermostat, you can follow this guide to learn how to reset any of your Honeywell Pro or non-Pro series thermostats easily.

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Joshua D'souza

Enjoy games, 90's hip-hop, and tech. Loves exploring the infinite world of laptops and food. Every ready to provide assistance in anything that rocks his boat. Will gladly enjoy capturing memories through various lenses. Worked previously at PiunikaWeb as an author and researcher.

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