If your front door key fell into the hands of third parties, such as construction workers, you should reprogram all the other keys. The kit that comes with a lock, usually 2 or 3 installation key, one key for reprogramming and 5-6 of ordinary keys. Mounting the keys, as a rule, and give builders, finishers and other unauthorized persons temporarily having access to the apartment. After completion of all matters requiring the presence of workers, open the door and in this position, insert the lock key to reprogram and rotate it a full 360 degrees first with internal and then the external side of the door. Then insert into the lock with an ordinary key from the set. Now mounting keys lock will not unlock, and the usual key will be able to work in normal mode.
To solve the problem of lost keys will help purchase a new set. For example, if you set the lock CIZA, such a set is called CISA CAMBIO FACILE. It includes 5 new unprogrammed key. Invite the masters of the company engaged in the installation of locks, it is with the help of the special tool will program the lock to new keys, and problems with the lock not to occur. Neither the keys or lock do not attempt to recode yourself. Unskilled work will lead to lowering of reliability of the castle or breakage. In extreme cases, carefully read the instructions and follow any consistently specified acts. Reprogramming key depends on the type of lock.
In General, the program change keys from all doors should be trusted only to specialists. Do not contact the dubious small company, as sometimes they are accomplices of the fraudsters, and you can't trust the security of your apartment. It is best to use the services of the same company that installed the lock on the door. In this case, you can not be afraid of burglars.