21 of 27 people found the following review helpful
Broken out of the box,
Verified Purchase(What's this?)
This review is from: First Alert CO615 Carbon Monoxide Plug-In Alarm with Battery Backup and Digital Display (Tools & Home Improvement)
I ordered three of these units due to the new CA law. Two out of the three were dead on arrival. They read ERR in the LCD which, according to the instruction novel, means there is a malfunction. There is no instruction on how to solve the problem so I returned all three.