We should start off by saying, gas furnaces are not inherently dangerous appliances. You should never panic just because you use a gas-powered appliance in your home. However, just like any other appliance or home comfort system, your gas furnace needs to be well cared for so you can avoid it becoming potentially dangerous.
The fact of the matter is, it produces combustion gasses when it operates and those combustion gases have the potential to lead to harmful consequences, such as carbon monoxide exposure. Treat your gas furnace well, and you should have few worries about its operation.
But an ill-maintained furnace could potentially suffer from expedited wear and tear, leading to a cracked heat exchanger, which is where problems happen. This is a more common problem in aging systems (10-15 years old) but is still something you should be aware of if you have a gas-powered system, no matter the age. So, what’s a heat exchanger and why is a cracked one bad news?