It is easy to reset your TYDOM password :

For TYDOM 1.0 press and hold the reset button (near the power cable) for about 15 seconds, or until the LED light flashes purple rapidly. When you next open the app, delete the old password and press connection with the password field blank. You will then be asked to enter your new password when you open the TYDOM app.

It is the same process for TYDOM 2.0. Put your alarm system into maintenance mode and remove the cover of the TYDOM 2.0. Press and hold the button 3 (on the right hand side) for about 15 seconds. When you next open the app, delete the old password and press connection with the password field blank. You will then be asked to enter your new password when you open the TYDOM app.