[RNajarian]

When I built my house 6 years ago I had hard wired smoke detectors installed. A smart idea to have these, they get their power from the house electrical system and have a battery backup for when the power is out.

OCCASIONALLY the entire system goes off. All the units are wired together so when one unit is triggered the rest all go off, it sounds like an air raid siren. I will find the unit that triggered the alarm, blow compressed air in the system then the alarm will shut off.

Last night the one of the units tripped the entire system. I was able to locate the unit which went off and tried to stop the alarm by blowing compressed air into the unit. No luck. I finally had to physically remove the unit, at that point the alarm shut down BUT the individual unit now operating on battery was still activated.

When I removed the battery it got quiet, I replaced the battery with a new one and it went off again.

QUESTION:
Is it common for a 6 year old smoke alarm to go bad? What could set it off (other than an actual fire)?

I've ordered a new unit, assuming this one is bad.