How to Install Eufy Smart Lock E31

Take a moment to inspect each part. If anything is missing or damaged, contact Eufy customer support immediately. It’s also a good idea to download the EufySecurity app (available on iOS and Android) before starting. You’ll need it for setup and calibration.

Step 1: Check Door Compatibility

Not all doors are suitable for the Eufy Smart Lock E31. Before drilling any holes, verify that your door meets the following requirements:

Door Thickness

The E31 is designed for doors between 1.38 inches (35mm) and 2.17 inches (55mm) thick. Measure your door using a tape measure. If it’s outside this range, the lock may not fit properly.

Backset Measurement

The backset is the distance from the edge of the door to the center of the deadbolt hole. The E31 supports two standard backsets: 2.375 inches (60mm) and 2.75 inches (70mm). Most modern doors use one of these, but double-check to avoid surprises.

Deadbolt Type

The E31 works with standard single-cylinder deadbolts. If you have a double-cylinder lock (requires a key from both sides), you’ll need to replace it first. Also, ensure your deadbolt is installed at least 6 inches (15cm) above the door handle for proper alignment.

Door Material

The lock is compatible with wood, metal, and composite doors. Avoid installing on glass or hollow-core doors unless reinforced, as they may not support the weight or drilling.

Clearance Check

Make sure there’s enough space around the door for the lock to operate. The exterior unit should not interfere with the door frame, weather stripping, or nearby hardware like door knockers or mail slots.

If your door passes all these checks, you’re ready to move on. If not, consider modifying your door or choosing a different smart lock model.

Step 2: Gather Your Tools

You don’t need a full toolbox, but having the right equipment makes the job easier and safer. Here’s what you’ll need:

• Power Drill: For drilling pilot holes and driving screws.
• Drill Bits: 1/8-inch and 3/16-inch bits for pilot holes.
• Screwdriver: Phillips head (#2) for tightening screws.
• Tape Measure: To confirm measurements and alignment.
• Level: Ensures the lock is straight.
• Pencil: For marking drill points.
• Masking Tape: Helps prevent wood splitting when drilling.
• Safety Glasses: Protect your eyes from dust and debris.

Optional but helpful: a stud finder (if drilling near the frame), a chisel (for minor adjustments), and a helper to hold the lock in place during installation.

Step 3: Remove the Existing Lock

If you already have a deadbolt installed, you’ll need to remove it before installing the E31. Here’s how:

Step 3.1: Unscrew the Interior Plate

Open the door and locate the interior plate of your current deadbolt. Use a screwdriver to remove the two screws holding it in place. Gently pull the plate away from the door.

Step 3.2: Remove the Exterior Cylinder

On the outside of the door, you’ll see the keyhole cylinder. Insert the key and turn it to the “unlocked” position. Then, pull the cylinder straight out. If it’s stuck, wiggle it gently while pulling.

Step 3.3: Remove the Deadbolt Mechanism

Inside the door edge, you’ll find the deadbolt itself. Unscrew the two screws holding it in place and slide it out. Keep these parts in case you ever want to reinstall the old lock.

Step 3.4: Clean the Area

Use a cloth to wipe away dust and debris from the hole. This ensures a clean surface for the new lock.

Now your door is ready for the Eufy Smart Lock E31.

Step 4: Install the Mounting Plate

The mounting plate is the foundation of your smart lock. It must be securely attached to support the weight and operation of the E31.

Step 4.1: Position the Plate

Hold the mounting plate against the interior side of the door, aligning it with the deadbolt hole. Use a level to ensure it’s straight. Mark the screw holes with a pencil.

Step 4.2: Drill Pilot Holes

Use a 1/8-inch drill bit to create pilot holes at the marked points. This prevents the wood from splitting when you drive in the screws. Apply masking tape over the drill points for extra protection.

Step 4.3: Secure the Plate

Align the plate with the pilot holes and insert the provided screws. Use a screwdriver or drill to tighten them firmly, but don’t over-tighten—this could strip the wood.

Double-check that the plate is level and secure. It should not wobble or shift when pressed.

Step 5: Attach the Interior Unit

The interior unit houses the battery compartment and connects to the exterior lock via a cable.

Step 5.1: Connect the Cable

Locate the ribbon cable on the back of the interior unit. Feed it through the door hole toward the exterior side. Be careful not to bend or pinch the cable.

Step 5.2: Align and Mount

Place the interior unit onto the mounting plate. The screw holes should align perfectly. Insert the screws and tighten them gradually, alternating sides to ensure even pressure.

Step 5.3: Install Batteries

Open the battery compartment on the interior unit. Insert four AA batteries, following the polarity markings (+ and -). Close the compartment securely.

The lock should power on automatically. You’ll see lights on the exterior keypad—this confirms it’s receiving power.

Step 6: Install the Exterior Unit

Now it’s time to attach the main smart lock body to the outside of your door.

Step 6.1: Connect the Cable

Take the ribbon cable from the interior unit and plug it into the corresponding port on the back of the exterior unit. It only fits one way—don’t force it.

Step 6.2: Position the Unit

Hold the exterior unit against the door, aligning it with the deadbolt hole. Make sure the keypad is upright and the fingerprint scanner is accessible.

Step 6.3: Secure with Screws

Insert the long screws through the exterior unit and into the interior mounting plate. Tighten them evenly using a screwdriver. Again, avoid over-tightening.

Once secured, gently tug on the unit to ensure it’s firmly attached.

Step 7: Install the Deadbolt Adapter

The deadbolt adapter ensures the lock engages smoothly with your door frame.

Step 7.1: Insert the Adapter

Slide the adapter into the deadbolt hole on the edge of the door. It should fit snugly around the bolt.

Step 7.2: Test the Bolt Movement

Manually turn the interior thumb turn to extend and retract the deadbolt. It should move smoothly without resistance. If it sticks, adjust the adapter or check alignment.

Step 8: Calibrate the Lock via the Eufy App

Calibration ensures the lock recognizes open and closed positions accurately. This step is crucial for reliable operation.

Step 8.1: Download and Open the App

If you haven’t already, download the EufySecurity app from the App Store or Google Play. Create an account or log in.

Step 8.2: Add the Lock

Tap the “+” icon and select “Smart Lock.” Follow the on-screen prompts to scan the QR code on the interior unit or enter the serial number manually.

Step 8.3: Start Calibration

The app will guide you through the calibration process. It typically involves:

• Closing the door completely.
• Turning the interior thumb turn to lock and unlock.
• Confirming actions in the app.

Follow each step carefully. The app will notify you when calibration is complete.

Step 9: Test the Lock

Before celebrating, test every function to ensure everything works.

Step 9.1: Manual Operation

Turn the interior thumb turn to lock and unlock. The deadbolt should extend and retract smoothly.

Step 9.2: Keypad Entry

Enter your default PIN (usually found in the manual) on the exterior keypad. The lock should respond with a green light and unlock.

Step 9.3: Fingerprint Scan

Place your registered finger on the scanner. It should unlock within seconds.

Step 9.4: App Control

Use the EufySecurity app to lock and unlock remotely. Check that the status updates in real time.

Step 9.5: Key Override

Insert one of the physical keys and turn it. The lock should operate normally—this is your backup in case of battery failure.

If any function fails, refer to the troubleshooting section below.

Troubleshooting Common Issues

Even with careful installation, you might encounter a few hiccups. Here’s how to fix the most common problems:

Lock Doesn’t Power On

Check that the batteries are inserted correctly and have charge. Reopen the battery compartment and reinsert the batteries. If the issue persists, try new batteries.

Keypad Not Responding

Ensure the lock is powered and the app shows it as online. Clean the keypad with a dry cloth. If unresponsive, restart the lock by removing and reinserting the batteries.

Deadbolt Sticks or Doesn’t Extend

This is often due to misalignment. Loosen the mounting screws slightly, adjust the lock position, and retighten. Also, check that the deadbolt hole in the door frame isn’t obstructed.

App Can’t Connect to Lock

Make sure your phone is connected to Wi-Fi and Bluetooth is enabled. Move closer to the lock and try again. If needed, remove and re-add the lock in the app.

Fingerprint Scanner Not Recognizing Prints

Re-register your fingerprint in the app. Ensure your finger is clean and dry during scanning. Avoid scanning with wet or dirty fingers.

Battery Drains Quickly

The E31 uses 4 AA batteries and should last 6–12 months. If draining fast, check for loose connections or extreme temperatures. Replace with high-quality alkaline batteries.

Final Tips for Long-Term Use

To keep your Eufy Smart Lock E31 running smoothly:

• Regularly clean the keypad and fingerprint scanner with a soft, dry cloth.
• Check battery levels monthly using the app’s battery indicator.
• Update the firmware when prompted in the app for security and performance improvements.
• Re-register fingerprints if you notice reduced accuracy.
• Keep the physical keys accessible in case of emergency.

Conclusion

Installing the Eufy Smart Lock E31 is a straightforward DIY project that pays off in convenience and security. By following this guide, you’ve upgraded your door with keyless entry, remote access, and advanced encryption—all without calling a locksmith. Remember to check compatibility, use the right tools, and test thoroughly after installation.

With proper care, your E31 will serve you reliably for years. Enjoy the peace of mind that comes with knowing your home is protected by smart technology. Welcome to the future of home security!