How do I fix my alarm very similar to a Gardtec 500 Series?

I have moved into a new flat which has a similar alarm system to a Gardtec 500 Series, which I have not had re-setted, however the other day the electric all went off in the flat so I re-set the Electric switch which caused the alarm to go off - I have taken the fuse out of the alarm box which stopped the ringing outside the house, however the alarm is silently going off inside the house what do I do to get rid of this noise as if the fuse has been taken out surely this should not be working ?? Please can someone help me as the ringing is driving me mad.