local authority smoke alarms

[frankmac]

Hi Guys ,friends house was rewired 3 yrs ago.........contractor installed 3 x mains powered smoke detectors with battery back up smoke detectors which can can be tested and silenced via double gang test switch...........problem ocurrs approx 9pm each evening ..........sounders start blasting will silence by operating test switch.maybe 30mins later same problem...........tried taking heads off one each evening still the same.Batteries cann`t be changed,good until 20016 so it say on head.
anybody any ideas................tried cleaning them.
Cheers Frankmac.

 

[bonjovi]

try going to pub befor 9 and you wont hear them and when you get back you wont care sorry not what you wanted to hear but after a few stellas best i can do
ok lets be serious give us the make and model and ill look into it