Slight issue, Installed Honeywell Accenta G4 in 2013 with Honeywell AG8 sounder. Having carried out walk teats on numerous occasions alarm seemed to work well including the occasional accidental setting off. Daughter forgot to disarm last week when walking downstairs. she entered code and alarm stopped on internal sounder, but external sounder would not disarm. Continued to ring for at least 5 mins. Then sounder stopped on its own. Could this be related to battery being nearly 5 years old.? or maybe something else.. Thoughts please !!! Not too bothered as alarm works as desired , just cant turn it off when i want to. Cheers JB