Although it is partly my fault for not persevering with the set up procedure (which I thought had been done) the system has never worked properly. In fact I never use my alarm system . . however I do intend to finally get to the bottom of how it works. After initial installation, an engineer returned as it was not functioning and seemed to fix it but after he left it reverted back to constantly giving me malfunction signals. I still do not understand the technicalities but I am sure I will have it working one day. If you have an installation, make very sure that it is functioning before the engineer leaves.