My house has a British Gas alarm system fitted when it was built (but never activated as I objected to paying the rip off installation fee and monthly charges). I've got itemised billing on my BT phone line and was checking the bill online last week and I noticed that the alarm makes the occasional call to an 0870 number!!

I complained to British Gas about this but they said that the alarm might have a fault and they can send an engineer out to investigate but as the alarm isn't activated and I don't have a contract it will cost around 85!!

I wondered if it would be possible for BT to somehow block the 0870 number but they just said it's nothing to do with them and wouldn't help me (I guess they're quite happy if it continues to make calls!).

I feel like I'm being scammed here. Either I've got to pay the British Gas "ransom" to get the alarm fixed or just let it continue making calls without my permission.

I had a look inside the alarm control box and there's 4 wires going into the PCB that come from the BT line. The terminals on the PCB are marked "RING", "TIP", "T" and "R" (or something very similar). I thought it would just be a simple job of disconnecting all the wires but when I did that the alarm started beeping and when I tried using the phone I couldn't get a dial tone so I had to re-connect it.

Is there a way to fool the alarm somehow? I wondered about pulling the fuse out of the alarm but I notice that it's got a battery backup inside the control box so I guess it'll complain like mad if I isolated it (until the battery ran out).