Problems with PIR's on aritech CS350 system

[guest]

I had a low battery first and the service engineer put in a new one, then the alarm went off again. The Error message was -System armed Events in log 04 PIRS. The Service engineer tracked down the fault and put in a new PIR in the Garage,orginally there were three PIR's Downstairs all which the engineer said were on the one circuit PIR O4, so the Engineer changed these onto three Circuits- sitting Room, Garage, Dining Room so if there was a problem with any other PIR i would know straight away which one was giving trouble. I came back last nite and the alarm had gone off again with the message- 03 Sensors US. I have some bare wires in two rooms for to connect up to future PIR's, would this have anything to do with it?. Last Nite, Ialso tried part setting alarm by turning off the three PIR's but the alarm went off after a minute again, is there any way of tracing fault?

[Admin]

From your zone description, 03 Sensors US.. This is zone input 3 & seems to be refering to sensors up stairs. Do you have sensors on the windows upstairs? Put the system on walk test zone 3 & try to establish what exactly is connected to this zone. The fact that there were a number of PiRs connected to the one zone does not say much for your service engineer. There should always be only one PiR per zone anyway.
Post a reply & let me know what you find.