Smoke detectors
 

We had a small kitchen fire which filled the house with smoke. The smoke detectors didn’t go off even though the batteries were new. Found out that the life expectancy of them is ten years. The fire dept won’t even replace batteries in older smoke detectors. We ordered a multi pack and replaced them ourselves. At this time the fire department isn’t replacing them, only if they are beeping. I guess our little kitchen fire was a blessing and found out before it was something serious.