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There are good reasons to place a lock on your thermostat and prevent the settings from being adjusted. The lock and unlock functions can help keep children from playing with it and messing up your perfect schedule!

We’ll guide you through what lockout modes you can activate on your Honeywell Thermostat, and how to unlock them. Whether you forgot how to or simply don’t know how, we have you covered!

Before we get started …

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The steps here work specifically for the Honeywell Pro Series & 8000 models.

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Explaining thermostat lock modes

For your Honeywell Pro Series thermostats, you can lock your keypad in either Full or Partial mode. You can find this setting by accessing the Menu, then Screen Lock.

Full (On), Partial (Part), and Off

While “Full” lock prevents any access to the thermostat settings, with a “Partial” lock you can change the temperature. Both modes can be unlocked using a PIN, code, or password.

Set your lock to “Partial” if you override the schedule often. Use “Full” lock if you just let the thermostat run on schedule. This way you’ll save time, but be sure to remember your lock code.

Your lock code will disable either lock modes set. Check the steps below on how to unlock your Honeywell Pro Series thermostat.

How to unlock

T4 Pro Series Programmable Thermostat

Unlock the keypad for your T4 Pro Programmable Thermostat using these easy steps:

  1. Press the center button labeled Unlock. You’ll then be able to input the default password, “1234”.
  2. Press the +/- buttons to change the digit. For example, change it to 1 for the first one.
  3. Press Select to set the digit.
  4. Repeat Steps 2 and 3 until you finish through the four numbers required.
  5. After pressing Select for the last digit, your thermostat will be unlocked and your settings are free to access again

T6 Pro Series Z-Wave Thermostat

Unlock the keypad for your T6 Pro Z-Wave Thermostat using these easy steps:

  1. Press the lock symbol on the display. You’ll then be prompted to enter the PIN number.
  2. Press the +/- buttons to change the digit.
  3. Press Select to enter the digit.
  4. Repeat Steps 2 and 3 until you finish through the four numbers required

When you enter the correct code, your thermostat will be unlocked. You’ll go to the thermostat home screen and have access to all settings

T6 Pro Series Smart Thermostat

Unlock the keypad for your T6 Pro Smart Thermostat using these easy steps:

  1. Press the lock symbol on the display. You’ll then be prompted to enter the PIN number.
  2. Press the +/- buttons to change the digit.
  3. Press Select to enter the digit.
  4. Repeat Steps 2 and 3 until you finish through the four numbers required.

When you enter the correct code, your thermostat will be unlocked. You’ll go to the thermostat home screen and have access to all settings.

T6 Pro Series – Can't Remember PIN Code?

The password, code, or PIN on your T6 Pro Series are only four digits. Despite this, it’s possible to forget them. You might not be using the thermostat that often, especially if your scheduling is sufficient enough. Or perhaps someone else configured the lock setting on it.

For the T4 Pro model, the code is simply 1234. But for the T6 Pro Series, follow these steps to recover it:

  1. Remove the thermostat faceplate and look for a four-digit code on the top right of the base.
  2. Add 1234 to this four-digit code.
  3. The sum will be your thermostat’s password or PIN.

Follow the steps above to unlock your thermostat using the PIN you recovered.

Honeywell 8000 Series Thermostat (Including VisionPro)

To unlock your RTH8500 Wi-Fi Series or TH8000 Series thermostats, follow these steps:

  1. Hold down System and Auto with two fingers on your display.
  2. Press and hold the blank lower center button, until the display changes. On some models, hold the 2nd and 4th blank buttons.
  3. Change the left values to 0670 using the up/down buttons in the middle of the display.
  4. Change the right value to 0 using the up/down buttons in the right.
  5. Press DONE on the lower right to confirm.

For other models like the VisionPRO TH8321WF or VisionPRO Series with RedLINK models (with the -R suffix):

  1. Press MENU.
  2. Locate Security Settings using the arrow buttons.
  3. Press Select.
  4. Enter your password using the arrow buttons.
  5. Press Done.

How to lock

T4 Pro Series Programmable Thermostat

Lock the keypad for your T4 Pro Programmable Thermostat using these easy steps:

  1. Press Menu on your thermostat display.
  2. Navigate to Lock by pressing the +/- buttons.
  3. Press Select.
  4. Press the +/- buttons to select your lock mode.
  5. Press Select to confirm your choice.

Your thermostat will be locked according to the mode you selected.

T6 Pro Series Z-Wave Thermostat

Lock the keypad for your T6 Pro Z-Wave Thermostat using these easy steps:

  1. Press Menu on your thermostat display.
  2. Navigate to SCREEN LOCK by pressing the arrow buttons.
  3. Press Select.
  4. Select between PARTIAL LOCK and FULL LOCK using the arrow buttons.
  5. Press Select to confirm your choice.
  6. Remember or write down the PIN number shown on the screen.
  7. Press Select, then finalize the settings by pressing Yes

Your thermostat will be locked according to the mode you selected.

T6 Pro Series Smart Thermostat

Lock the keypad for your T6 Pro Z-Wave Thermostat using these easy steps:

  1. Press Menu on your thermostat display.
  2. Navigate to SCREEN LOCK by pressing the arrow buttons.
  3. Press Select.
  4. Select between PARTIAL LOCK and FULL LOCK using the arrow buttons.
  5. Press Select to confirm your choice.
  6. Remember or write down the PIN number shown on the screen.
  7. Press Select, then finalize the settings by pressing Yes.

Your thermostat will be locked according to the mode you selected.

Honeywell 8000 Series Thermostat (Including VisionPro)

To lock your RTH8500 Wi-Fi Series or TH8000 Series thermostats, follow these steps:

  1. Press System on your display.
  2. Press and hold the blank lower center button, until the display changes. On some models, hold the 2nd and 4th blank buttons.
  3. Change the left values to 0670 using the up/down buttons in the middle of the display.
  4. Change the right value using the up/down buttons on the right.
  5. Choose 1 for Partial lock and 2 for Full lock. 0 removes any lock from the thermostat.
  6. Press DONE on the lower right to confirm.

For other models like the VisionPRO TH8321WF or VisionPRO Series with RedLINK models (with the -R suffix):

  1. Press MENU.
  2. Locate Security Settings using the arrow buttons.
  3. Press Select.
  4. Navigate using the arrow buttons. Then, select either Change Lock Mode or Create Password.
  5. Press Done. If you created a password, make sure to remember or write it down.

Conclusion

Locking your Honeywell Pro Series & 8000 Thermostats lets you have control over who can change its settings.

There are 3 lock modes on your thermostat. The Full lock disables any access to it, Partial enables changing the temperature, and you have the unlocked setting.

The steps for how to lock and unlock are similar but vary depending on your Honeywell Pro Series or 8000 thermostats. Most of them require a PIN, code or password to unlock so make sure to remember them.

Hopefully, this article has enabled you to take advantage of this feature on your Honeywell thermostat.

Sources

Honeywell Thermostat Manuals
Honeywell Home

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