Bests & Worsts Reviews from Amazon

I purchased this product in 2015. I test the unit on a regular basis by pressing the reset/test button. Tonight I smelled something odd in an unfinished area of the basement. I took the unit to that area and left it there for 30 minutes. The display NEVER changed from 00. We opened the windows to try to air out the room. After contacting the utility company, we checked the garage which was above the unfinished area of the basement. THE CAR WAS RUNNING AND HAD BEEN RUNNING FOR 5 HOURS WITH THE GARAGE DOOR DOWN!!!! So, we took the carbon monoxide alarm to the garage to see if we could get the reading. NOTHING. Pressed the reset/test button to check it and it alarmed as expected. When the utility man arrived, the highest rating that his device detected throughout the house was 10 Parts Per Million. He said, "what I know for sure is that you would have been dead by the morning." I do not know why this device did not work but I hope that this will get the attention of the company so that lives can be saved.