Prerequisites:

1. Make sure the smart door lock is powered up using fresh batteries. If it doesn't power up, refer to the Why is my Smart Door Lock not powering up? article.

2. Make sure the lock is configured (see this article to configure the lock).

Read before you start troubleshooting. 

If the troubleshooting steps in this article do not resolve the issue, please send us the following so we can assist you further. You are welcome to capture the necessary images and recordings as you work through the troubleshooting process, which will help us assess the situation more efficiently.

1. A short video demonstrating the issue.

2. A photo of the back of the front panel clearly showing how the door opening direction has been set (Depending on the model it could be the arrow head on the spindle socket, the L/R switch, the L/R screw).
3. Screen shot of the lock settings to show the door opening direction has been set correctly (Only applicable to SDL-R1, SDL-R2, SDL-PP1 and SDL-PP2).

3. A screenshot of the lock settings showing the Auto-lock and Passage mode settings.
4. Photos of your door and the lock from different angles showing the alignment
5. Video of testing the lock with the back panel off the door. Make sure you leave the door open during testing so we could see the locking mechanism in action.
6. A video of the 6th troubleshooting step below.

1. It could be an installation error (Not applicable to SDL-H1). If you have a right swing door and the lock has been installed as a left swing door the door will open from the outside every time. The same if you have a left swing door and the lock has been installed as a right swing door. Check sections 3 and 4 of the Installation Guide for the direction settings. These are some common Installation and User Guide links. 
   Smart Medium - Fingerprint and Keyless Entry Mortise Lock (SDL-H2)
   Slim - Fingerprint and Keyless Entry Smart Mortise Lock [43mm wide] (SDL-S1)
   Slim - Fingerprint and Keyless Entry Smart Mortise Lock [38mm wide] (SDL-S2)
   Super Slim - Fingerprint and Keyless Entry Smart Mortise Lock [35mm wide] (SDL-SS1)
   
   If you have a SDL-T1 purchased before 06/02/2026 - the door opening direction is determined by a switch at the back of the interior panel and a setting in the TTLock app.
   
   If you have a SDL-T1 purchased after 06/02/2026, SDL-PP1 or SDL-PP2 - the door opening direction is set in the TTLock app under settings of the lock.
   
   
2. It could be that you have turned off the auto-lock. If auto-lock is off you need to lock the door manually by pressing and holding the # key or by pressing and holding the large padlock icon on the app (see this article for more information).
   
   
3. It could be that it is in passage mode. To lock the door during passage mode you need to lock the door manually by pressing and holding the # key or by pressing and holding the large padlock icon on the app (see this article for more details).
   
   
4. Check the lock alignment (see this article for more details).
   
   
5. If the spindle is too long for your door thickness it could create too much friction resulting the spindle not to move freely. 
   To check if the spindle is too long for your door thickness, test the lock with the just the back panel off the door.  Also, check the parts list in the User Manual to see which spindle is suitable for your door thickness. You can either select a smaller spindle size (if possible) or trim the spindle using a grinder (Do this with caution and do not over-shorten the spindle). 
   
   

6. Sometimes new locks come in the mechanically unlock state from the factory. Lock the door with the mechanical key first (If you can pull the key out of the key hole, it means you have locked it correctly). Now unlock with the key, then lock electronically by pressing on the # key on the keypad or  by using the TTLock app. 
   

If you have any further questions or need additional support, please don't hesitate to contact our team.