Master Lock 5423EC
Master Lock 5423D Wall Mount Push Button Key Lock Box Instruction Manual
Model: 5423EC
Introduction
This manual provides comprehensive instructions for the installation, operation, and maintenance of your Master Lock 5423D Wall Mount Push Button Key Lock Box. Please read these instructions carefully before use to ensure proper function and security.

Image: The Master Lock 5423D Wall Mount Push Button Key Lock Box, featuring a silver keypad with black buttons and a black weather-resistant housing.
Setup
1. Wall Mounting Installation
The Master Lock 5423D is designed for permanent installation on a wall or fixed object. Mounting hardware is included with the product.
- Select a suitable location for installation, ensuring the surface is secure.
- Open the lock box to access the mounting holes located on the back plate.
- Use the provided hardware to securely fasten the lock box to the chosen surface.

Image: A detailed view of the Master Lock 5423D, highlighting its wall mount design, push-button keypad, storage compartment for keys, and protective weather cover.
2. Setting Your Combination
The lock box allows you to set your own personalized combination. Follow these steps to configure your code:
- Open the lock box and locate the yellow Recode Tool inside.
- On the back of the keypad, locate the buttons. All arrows on these buttons should initially be set to the "SET OFF" position.
- Using the Recode Tool, push and turn the desired buttons 180 degrees (1/2 turn) to the "SET ON" position. These will be the numbers in your combination.
- Ensure the button is properly set when it pops up.
- Your combination can consist of any sequence of the selected numbers. The order of entry does not matter; only that all selected numbers are pressed.

Image: A four-step visual guide demonstrating how to set the combination for the Master Lock 5423D, showing the Recode Tool and the 'SET ON'/'SET OFF' positions.
Operating Instructions
1. Opening the Lock Box
- Slide the protective weather cover upwards to reveal the keypad.
- Enter your combination by pressing the selected buttons.
- Depress the lever located above the keypad and pull the door open.
2. Storing Keys
The interior compartment is designed to securely hold up to five standard keys or key fobs. For optimal fit, ensure keys are arranged flat within the compartment. A small hole in the back of the compartment allows for attaching a hook (not included) to hang keys, preventing jamming.

Image: A comparison showing the secure method of storing keys in the Master Lock 5423D versus insecure methods like under a doormat or in a plant pot.
3. Closing the Lock Box
To close and secure the lock box:
- Place keys securely inside the compartment.
- Close the door of the lock box.
- Re-enter your combination and depress the lever to ensure the locking mechanism engages. The door will not close without the combination being entered again.
- Slide the protective weather cover back down over the keypad.
Maintenance
The Master Lock 5423D is constructed with a durable metal body and features a protective weather cover. To ensure longevity and reliable operation:
- Regularly check that the weather cover is properly positioned to protect the combination buttons from environmental elements, preventing freezing and jamming.
- Keep the keypad clean from dirt and debris. Use a soft, damp cloth for cleaning. Avoid abrasive cleaners.
- Inspect the mounting for any signs of loosening and re-secure if necessary.
Troubleshooting
- Combination Not Working: If you accidentally press an incorrect button while entering your code, pull down the thin black tab (the clear button) to reset the keypad. Then, re-enter your combination.
- Difficulty Closing: The lock box requires the combination to be entered before both opening and closing. Ensure you re-enter your code after placing keys inside to properly secure the door.
- Keys Jamming: The interior storage is designed for keys to lie flat. If using a keychain or multiple keys, you may need to adjust their position to allow the door to close without obstruction. Consider utilizing the small hole in the back compartment to attach a hook for hanging keys.
- Lock Box Appears Used or Malfunctioning: If the product arrives in a condition that suggests prior use or if it fails to operate as described, verify that the reset tool is present and that the locking latch engages correctly. Contact customer support if issues persist.
Specifications
| Feature | Detail |
|---|---|
| Brand | Master Lock |
| Model Name | 5423EC |
| Lock Type | Combination Lock (Push Button) |
| Material | Aluminum |
| Color | Black |
| Exterior Dimensions (H x W x D) | 4-5/8 inch (11.7 cm) x 3-1/8 inch (7.9 cm) x 2-1/16 inch (5.2 cm) |
| Interior Dimensions (H x W x D) | 3-1/2 inch (8.9 cm) x 2-1/4 inch (5.7 cm) x 1 inch (2.5 cm) |
| Interior Volume | 7.9 cubic inches (20 cubic cm) |
| Item Weight | 1.7 pounds |
| Special Feature | Portable, Weather Cover |
| Mounting Type | Wall Mount |

Image: A diagram illustrating the exterior and interior dimensions of the Master Lock 5423D, including measurements in inches and millimeters, and indicating capacity for house keys, access cards, and key fobs.
Warranty
The Master Lock 5423D Wall Mount Push Button Key Lock Box comes with a Limited Lifetime Warranty. For specific terms and conditions, please refer to the warranty information included with your product packaging or visit the official Master Lock website.
Support
For further assistance, technical support, or warranty claims, please contact Master Lock customer service. Contact information can typically be found on the product packaging or on the official Master Lock website (www.masterlock.com).
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