The dang thing has been rarely doing the 3 chirp code a couple times during the day for the better part of a week now. Our cat is really frightened by the sound and I fairly quickly had a suspicion which one was throwing the chirps but I couldn’t catch it in the act to be sure, and it was otherwise ambiguous which one was at fault and there were no LED codes to help.
Finally confirmed it today. 10 years and 1 month past date of purchase. 10 year warranty. Figures.
Smoke alarms have a 10 year lifespan, so if you have any others the same age you should be replacing them all.
Good call. There are a good number of them so I’ll add this to the budget.