Carbon Monoxide Detector Going Off

Dad must have got the first one ever made, and he's been dead 15 years now.  He's the one who put it downstairs, so I have no idea how old this carbon monoxide detector is. It's a plug in type so it's not the battery causing the problem.

Hmmm.

No one is suffering any headaches and we didn't die yet.

Brother in law brought over another one to plug in for the night to see if that one sounds an alarm tonight.

Could be the hot water heater. I'm not sure why.  But we need a hot water heater anyway. Not that it leaks but it's old and it will leak someday and I don't really want to ruin everything in the cellar AND buy a hot water heater.

Something to think about as I lay in bed tonight waiting to hear the alarm.