Why Does My August Smart Lock Keep Failing Calibration or Not Lock Fully?

Problem Description

Your August smart lock fails calibration or does not fully extend the deadbolt when locking. The lock motor runs but stops before the bolt is fully extended. The app shows jammed or calibration failed. You have tried recalibrating multiple times but it keeps failing. The lock worked fine initially but now struggles.

Why This Happens in Real Homes

When August calibration fails and the lock won't fully lock, the deadbolt is the usual culprit: calibration needs to reach a clean fully-locked stop, and a bolt that binds on a misaligned strike or a stiff thumbturn stops the motor short, so the lock never learns a proper locked position. The Smart Lock is only as good as the deadbolt it's turning.

Test the deadbolt by hand — it should throw all the way into an aligned strike without resistance; fix any binding or stiffness (a little lubricant helps) and align the strike. Make sure the adapter grips the thumbturn without slipping, the lock is mounted square, and the batteries are fresh, then recalibrate with the door closed. With a free-moving bolt, calibration completes and the lock throws fully.

Symptoms

• Calibration fails
• Doesn't fully lock after calibrating
• Bolt stops short
• Jams during calibration
• Motor strains
• Won't complete setup
• Repeated calibration attempts
• Reports locked but bolt not thrown

Recognize these? Here's what usually causes it.

Common Causes

• Deadbolt binding against the strike
• Thumbturn stiff / high resistance
• Adapter slipping
• Low batteries
• Lock not mounted square
• Door not closed during calibration
• Stiff or misaligned deadbolt
• Firmware issue

Tools & Requirements

Step-by-Step Solution

1

Check Door Alignment

Close your door and manually operate the deadbolt without the August lock attached. Does it lock smoothly? If the manual deadbolt requires force your door is misaligned. Adjust door hinges or strike plate position until the deadbolt operates smoothly by hand. Then reinstall August.

Needed for this step

Hillman 703185 Graphite Tube 3G, White Key Lock...

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$5.97

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2

Enlarge Strike Plate Opening

The deadbolt may be hitting the edge of the strike plate hole. Remove the strike plate and use a file or chisel to enlarge the hole by 1/8 inch on all sides. This gives the deadbolt clearance to extend fully. Reinstall strike plate and test manual operation.

Needed for this step

ATM Manual Reset Fuse Kit Low-Profile Mini Fuse...

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$24.41

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3

Verify Adapter Selection

August includes multiple adapters for different deadbolt thumbturn sizes. The wrong adapter causes slipping or incomplete rotation. Remove the lock and check that the adapter grips the thumbturn tightly. Try a different adapter if included in your kit.

4

Replace Batteries

Even batteries showing some charge may not provide enough power for the motor under load. Replace all batteries with fresh name-brand alkaline batteries not rechargeable. Low batteries are the most common cause of calibration failures and jam errors.

Needed for this step

Energizer Ultimate Lithium AA Batteries, Long L...

This helps complete the fix you are currently reading.

$83.98

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5

Lubricate Deadbolt

Friction in the deadbolt mechanism increases over time. Apply graphite lubricant or lock-specific lubricant to the deadbolt. Insert key and operate lock several times to distribute lubricant. Do not use WD-40 as it attracts dust. Proper lubrication reduces motor strain.

Quick Solutions

Still having issues? This is usually the deeper cause below.

Need More Help? August Home Support

Note: The contact information below connects you directly to August Home's official customer support team, not Trunetto. They can help with warranty claims, device replacements, and advanced technical issues.

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