I bought one of these years...........ago and it worked fine for years................ This NEW one was just like my old one--which is why I bought it. BUT, the NEW one only worked on ONE of the two alarms sounds. I have installed it since the old one no longer seems reliable. The NEW one seems to be working on ONE alarm sound. If it dies, I will go to a hardware store for something else. If it weren't so much trouble, I would request a replacement or refund.