Heating systems that use natural gas or propane as their fuel are highly efficient at converting the gas into heat. One downside of these systems is that the combustion of gas creates byproducts such as carbon monoxide.
In order to keep you safe, your heating system has several built-in features that control the gas supply and alert you if there is a problem.
Gas furnaces are equipped with a supply control valve. In the event the pressure in the gas supply pipes becomes too high, the valve can cut off the supply of gas and shut down your heating system. This helps to avoid a sudden burst of flame or the presence of gas that was not fully burned.
Pilot Light Controls
Today's newest gas furnaces do not use pilot lights that must stay constantly lit. However, if your heating system is more than 10 years old, it may have one of these pilot lights. If the flame goes out, the furnace has an automatic shutoff valve to stop gas from flowing into your home. You may even smell a small amount of natural gas that did not burn. The presence of this smell then gives you the opportunity to call for repair.
Carbon Monoxide Detectors
The newest gas furnaces include hard-wired carbon monoxide detectors. These detectors should be installed on every level of your home and hard-wired together so if one goes off, all of them will sound. These detectors have loud alarms that will wake you up if there is a measurable amount of carbon monoxide in the air. It is important to have these detectors installed because carbon monoxide gas has no odor or color.
How Do I Make Sure My Gas Appliances Are Safe? , ct.gov