3 Pack Portable Carbon Monoxide Detectors, CO Gas Detector Alarm with Advanced Digital Display LED Light, First Alert Carbon Monoxide Detector for Home, Office, Hospital, Restaurant etc.

First I want to say I am given these products for review by Amazon, not the manufacturer, all reviews are my own. These carbon monoxide alarms were received this morning then installed an hour later and possibly already saved my future life. If nothing else, they definitely forced me to take carbon monoxide detectors/alarms more seriously. My work history includes property repair that includes installing furnaces. I was taught 45 years ago that after installing a furnace to check my work to ensure safety for residence. I would test the heat exchanger by tossing in what I called smoke bombs into the heat exchanger to check for cracks and if smoke escaped the combustion chamber, there is a problem. These types of detectors were not available then and have been fairly expensive until the past decade. I already have a hard wired detector in my utility (furnace) room. I got these for my 2 bedrooms and garage (workshop). 6 months ago, I replaced the furnace in the workshop. I performed all my carbon monoxide and gas leak checks then let it run with no problems. This is the first time I put a CM alarm in the workshop. 10 minutes after setting the alarm on a chair 16 feet away from the furnace, the alarm goes off. I was confused as hell, couldn’t understand why. Instruction say not to put the alarm in a garage but there are no vehicles or anything else that produce carbon monoxide here. My first thought was this detector must be defective so I brought out another one. Within 7 to 10 minutes, the second alarm started going off also. I thought, what the hell, I have passed out many times in my shop. Ok, so what, I’m getting old, they were naps. ? I’m trying to understand how my instructor could have been so wrong in telling me to use these smoke bombs. (I can’t remember the actual name) anyways, the furnace is turned off until I find another one this summer. I will then completely disassemble this furnace to check everything to figure this out. The pros are : very loud, scared the doggie do-do out of my dogs. It will be a long time before they come back in here. a blinking green LED light to show its in operation. It will tell you with short beeps when the batteries need to be replaced, I don’t know yet how long that will take but normally a year. The only con about these is each alarm takes 3 AA batteries but well worth it, especially if the alarm goes off. I will add more as I learn. These are the only pictures that matters since I did not have the ability or presence of mind to take pictures of the alarm sounding because it scared me as much as the dogs.?