I realize polygraph test are not always accurate, but for the most part, they are. Everyone needs to go through a lie detector before getting on a plane.
Normal, residential, hard-wired smake alarms have 3, 14 wires to them. The wires are usually 120 VAC Black-Hot, White-Neutral, 0/9 VDC Red-Interlock. Those wires get wire-nutted onto small (18?) wires with a plastic end fitting to connect with the alarm. Often, the red wire gets changed into yellow. Normal, residential heating boilers are only controlled by the safeties on the boiler and a 24 VAC external thermostat. I have NEVER heard of a household boiler connected to the smoke alarms. You are going to have to review the wiring diagram on the back of the boiler's access cover. Similarly, you need to research the alarms. It is remotely possible that a contractor for a monitoring service (like ADT, et al.) wired low voltage smokes in that way.
Carbon monoxide is caused by incomplete combustion. The CO really really wants to become CO2 so it binds to oxygen. So when we breathe it in, it deprives our body of oxygen and kills us. It has no color or smell. Most household appliances like fridges, heaters, furnaces, etc, don't emit this gas. Although it could be a product of a malfunction. Just get a CO detector. It looks and sounds like a smoke detector, but when this one goes off and it seems like nothing's wrong, you take it seriously instead of looking at it like another idiotic smoke detector with low battery.
If you pull the hose off the back they'll probably fly out when you turn it on. Caps have such little pyrotechnics that if you were trying to start a fire youde have a heck of a time starting one.
