Do not have a dial tone on your phone when you have the Call Blocker connected,
Reason for this
This will be due to set up.
Please make sure that you are using your main telephone cable that is plugged into the master socket. Standard set up - Unplug this line cable from the base of the telephone and insert into the LINE port of the call blocker, then with the small black cable insert this into the TEL port of the call blocker and back into the base of the phone.
To generate a dial tone on a cordless DECT handset, double tap the Talk/Call/Dial button on the phone or press and hold for around 5 seconds