Bests & Worsts Reviews from Amazon

Purchased a six pack for replacements of my 18 year old units, which by the way never gave us any problems. Replaced them all in December of 2017. Three months later (late February) as we were preparing to leave home for an appointment they all started going off and would not stop. Do you know how difficult it is to find which one is causing the false alarm? After running up and down the steps from the basement to the second floor, unplugging all of them (8 total, we also have two photoelectric sensors) I finally found the one causing the problem. I replaced the battery, only to have them go off again a few short minutes later. Ordered a new one and replaced the defect. Fast forward to July 1st, sleeping nicely at 6 am on a Sunday morning and here we go again, they all start chirping. This time it only lasted for about five minutes, enough time for me to run up and down the stairs looking for smoke or fire and the beeping stops. Of course, this wasn't enough time for me to find the defect. Now we get to go to sleep every night wondering when it's going to happen again. At least I have the confidence of knowing that when we're away we have another model hooked directly to our home alarm system, which will give us an alert over our cell phone. I just hope that a false alarm won't drive our parrot absolutely crazy if we're not at home. Time to look for another brand or model.