On the Bauer lock. IF you pull the door handle BEFORE you enter the code because you want to check to see if it is unlocked----YOU MUST THEN PUSH THE DOOR TO SHUT IT TIGHTER AGAIN. Do not do that and when you enter the code the pressure on the deadbolt will not allow it to move. As another poster stated, once you replace the batteries you must use the 3715 code until you reset to a new code. The beep is extremely hard to hear as is seeing the buttons lighting up. You can leave the door open and test the open and close and watch the deadbolt move in and out. There is NO fuse on this system. I have replaced numerous AA batteries that the customer SWORE were new and good but all 4 were all at 1.3 to 1.4 volts instead of 1.5 or higher. Then the Bauer worked. Doug