Owner’s How-To Guide
Master Lock Box Reset: How to Change the Code
A Master Lock box reset is straightforward when you have the current combination and the model uses a reset lever. Use these steps for a 5400D-style box, and check the manufacturer’s instructions if your model differs.
- Use your current combination
- Set a new code with the box open
- Test the code before closing the box
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What You Need Before a Master Lock Box Reset
Take a moment to prepare before changing the code. Keep the box open while you set and test the new combination; that way, you can correct a missed step without locking yourself out.
- The current combination — You need the combination that currently opens the box. These steps are for an owner who can already open it, not for bypassing a locked box.
- The correct model instructions — The reset-lever sequence below is for a 5400D-style Master Lock box. Find the model number on the product and compare its directions with the Master Lock support manuals before you begin.
- A new combination you can remember — Choose a code that is easy for you to recall but not an obvious sequence. Avoid closing the compartment until you have tested the new code successfully.
- A clear view of the reset mechanism — Open the compartment and locate the reset lever on the inside of the door. If your box has a different reset control, stop and use the instructions for that exact model.
How to Change the Code on a 5400D-Style Master Lock Box
Follow this sequence only if your box has the reset lever described above. The lever’s direction and location can vary between models, so use the product-specific manual for a different design.
- Set the dials to the current combination — Turn each number wheel until the existing code lines up with the indicator. Check every wheel before trying to open the compartment.
- Open the compartment door — Press the release button to open the door. Keep the box open throughout the reset and testing process.
- Find the reset lever inside the door — Look over the inside of the open compartment door for the small reset lever. Do not force a control that does not move as shown in your model’s instructions.
- Move the lever into the reset position — On a 5400D-style box, push the lever to the left and down. This places the mechanism in the position for setting a new combination.
- Turn the wheels to your new code — Rotate each number wheel to the desired digit, making sure every number lines up clearly with the indicator. Keep the wheels steady while you reset the lever.
- Return the lever to its original position — Push the lever up and to the right, back to its starting position. The code change is not complete until the lever is fully returned.
- Close and test the door while the box is still empty — Close the compartment door, scramble the wheels, and enter the new combination. Press the release button; the door should open. Repeat the test before putting anything inside.
- Scramble the wheels after the successful test — Once you have confirmed the new code opens the door, scramble the dials again. Close the protective cover, if your model has one.
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Why a Master Lock Box Code Change May Not Work
If the new combination does not open the box, keep the compartment open if you still can. Check the model-specific instructions before making another change.
The wrong reset sequence
Not every Master Lock box uses the same reset control or lever movement. Compare the product number and procedure with the manufacturer’s instructions rather than forcing the lever.
A wheel did not line up
A number sitting between positions may prevent the mechanism from recognizing the combination. With the door open, align each wheel carefully and test again.
The lever did not return fully
If the lever remains in the reset position, the new code may not have been saved as intended. Return it to its original position as shown for your model, then test with the door open.
The box is stiff or damaged
Do not force a stuck release button, wheel, or lever. Stop if the mechanism resists normal movement; forcing it can make the problem harder to resolve.
When to Call a Locksmith About a Master Lock Box
Call a locksmith if you have the current combination but the box will not open, the reset lever is stuck, or the model’s instructions do not match its controls. We’re a mobile locksmith open 24 hours a day, seven days a week, and we come to you rather than operating a storefront. For help with a Master Lock lock box or another lock issue, contact us at (385) 853-5247.
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Frequently asked questions
Can I change the combination while the Master Lock box is closed?
No. For the reset-lever procedure, you need to open the compartment with the current combination and keep it open while setting and testing the new code. Do not close it until the new combination has opened the door successfully.
What should I do if my Master Lock box has no reset lever?
Do not use the lever directions on a box with a different control. Check the model number and the instructions on Master Lock support for the procedure that matches your box.
Why does my new combination fail to open the box?
A wheel may be between numbers, the reset lever may not have returned to its original position, or your model may use a different reset process. If the compartment is still open, check the model’s directions and test the code again before putting anything inside.
Can a locksmith help if I know the code but the box will not open?
Yes. If the known combination does not release the door or a control is stuck, a locksmith can assess the lock box. We provide mobile locksmith service and are open 24/7.
Need Help With a Master Lock Box?
Call 24/7 Locksmith Salt Lake City at (385) 853-5247 for mobile locksmith help.