I live next door to the family of techno cretins who had their son and his friend instal one of these systems. From day one it has gone off for lengthy periods without warning and the elderly male of the family has struggled to shut the siren down. It seems that only the son who lives a few houses away is capable of hitting the on/off switch to silence the thing. Last night was the absolute end. I woke up at 2.30 a.m. to hear the system going off full blast, this continued until 5 a.m. when I fell asleep sitting up, from sheer exhaustion. When I woke again it was 7 a.m. with the darned thing still shrieking it's loudest. Just before 8.30 the son decided to walk across the road to silence the thing, although he must have heard it from his house. Then he left for work in his car but five minutes later the siren went off again. He must have again shown his father how to switch it off because 10 minutes later it was silent.

I think that anyone who buys one of these systems and thinks it will work is out of his mind. A neighbour has told me that some of her neighbours further along the road have fitted similar systems, with similar problems.

I have an alarm system fitted by a reputable company, maintained and monitored by them for £25 a month. It cost £2,500 to fit but worth the money because it actually works efficiently. In over 2 years I have had no false alarms, except when my dogs triggered it off while chasing a cat that wandered into our house. I switched off and reset it, but 2 minutes later the monitoring company rang to check that everything was allright.

So far as I am concerned, you get what you pay for and these cheap and cheerful systems bought from the local DIY are worse than useless.