First Alert SLED177 Hardwired Hearing Impaired Led Strobe Light , white

Should have looked at the reviews at the on set of trouble shooting my installation problems. It would not work as described & diligent study of the inclosed literature said NOTHING of the conditions I was seeing. I called the customer service number in literature. Was only on hold 10 minutes or so when a lady answered. She was able to look up my condition & told me to operate a switch on the back of the detector. WHAT SWITCH? There is no mention of a switch in the literature except the Disable Switch. Sure enough there is a small paddle the same color as the rest of the housing. Another reviewer called it a “shipping switch”. Pushing the paddle and “wall-a” my detector was now functioning properly. Installation was not a problem. My near deaf mother-n-law can hear the audio alarm as well as see the light which seems pretty bright. Cannot speak to the premature “end of life” alarms but thinking this “shipping switch” may be a recent addition and an effort to eliminating these “e o l” alarms and get more life out of the detector. Time will tell.