The cause is one of the followings.

 

1

Smartphone's Bluetooth function might be turned OFF. 

Please turn ON the Bluetooth function via smartphone setting screen.

 

2

The smartphone might be outside of transmission area.

The operation distance might vary upon the nearby surroundings and obstacles.

Please change the location before trying again.

 

【Caution】
Operation by application is based on the usage distance that the eye can see. (within 10 meters) However, please keep in mind that the area can be extended further due to the characteristic of Bluetooth. 

 

3

The smartphone registration might be deleted by someone else using the application.

Please check if other family members have deleted the registration and register the device again.
How to register

 

4

There might be a defect occurred inside door panel. 
Please press and hold the register button on the door to enter registration mode.
After registration mode is over, please try to operate on the door by using application again. 

 

5

There might be an abnormality in door's power source.

【When using batteries】
Please reinsert batteries in correct manner or change the batteries.
How to change batteries

【When using AC adapter】
Please make sure that the AC adapter is connected with the power outlet.

【When using controller unit】
Please make sure that controller unit's power is turned ON.