I have an old furnace FAG (Forced Air Gas) furnace which is 40 yrs old.
I called the utility company and asked if they would come over and check it to see if it was operating safely and they did so today.
They turned on the furnace and took readings at each vent in each room and everything is fine.
There is no charge for this service.
The tech noticed my carbon monoxide detector and said they need to be replaced every couple of years.
He commented that the detectors were not really that accurate as they would have a false reading, for example, from cigarette smoke.
Other false readings come from cleaning solutions such as amonia.
Other false readings even come from air fresheners or from incense.
I’m scratching my head and wondering if it’s worth it to even buy another CO detector.