If it works in walk test it is probably connected correctly.

Is it in the programme that you are setting prior to making a full test, i.e. it's no good trying to test a detector on the landing if you've set it as bedtime part set!

Hav you programmed it into the system as a security zone?

Assuming that all other detectors cause an alarm activation when the system is set, it must be a programming issue whereby the detector is not in the programme you are setting, or it's not programmed as a zone that will cause an alarm activation.

sorted it put it in zone 3 and closed zone 2 programmed zone 2 as not in use and 3 as guard zone now works a treat thanks for the help everyone really appreciate it

sorted it put it in zone 3 and closed zone 2 programmed zone 2 as not in use and 3 as guard zone now works a treat thanks for the help everyone really appreciate it

Yeah that would probably do it on an Avanti