Warning signs to watch for: An unexplained headache, dizziness, nausea, or fatigue that seems to improve when you leave the house (classic carbon monoxide poisoning symptoms), a carbon monoxide detector alarm, unusual smells when the heating system runs, visible cracks or corrosion on accessible parts of the furnace, or the pilot light frequently going out.
Prevention: Install carbon monoxide detectors on every level of your home and near sleeping areas, and test them monthly. Schedule annual professional HVAC maintenance specifically including a heat exchanger inspection. Replace aging HVAC systems before their components fail — most heat exchangers have a lifespan of 15 to 25 years.
Hazard #5: Improper Gas Pressure and Fuel Line Leaks
For gas-powered HVAC systems, the proper regulation of gas pressure is absolutely critical for both efficiency and safety. Gas pressure that is either too high or too low creates a cascade of dangerous conditions. When gas pressure runs abnormally low, it causes condensation to develop inside the heat exchanger — moisture that promotes corrosion, reduces efficiency, and shortens the system's lifespan. When gas pressure runs excessively high, the heat exchanger becomes dangerously overheated. An exchanger running at extreme temperatures is, quite literally, a fire waiting for an opportunity to ignite.
Fuel line leaks represent perhaps the most immediately dramatic hazard on this list. When oil or gas leaks from a fuel line and comes into contact with any of the hot components inside the HVAC system — burners, heat exchangers, or even overheated electrical components — the result is a fire that can spread rapidly and with tremendous intensity. Gas leaks also create the risk of accumulation in an enclosed space, where even a small spark can trigger an explosion. Improperly fitted gas connections are a particularly common source of leaks, especially in systems that have been installed by unqualified individuals or that have not been professionally inspected for extended periods.
Warning signs to watch for: The distinctive rotten egg odor of natural gas near the system (never ignore this — evacuate immediately and call the gas company), unexplained increases in gas bills, a hissing sound near gas lines or connections, dead vegetation in a line near buried gas pipes, or an HVAC system that repeatedly fails to ignite or maintain its flame.
Prevention: If you ever smell gas near your HVAC system, do not attempt to investigate it yourself — evacuate the area immediately, avoid using any electrical switches or open flames, and call your gas utility provider from outside the building. Have gas pressure checked and verified during every professional maintenance visit. Never allow unqualified individuals to install or modify gas connections on your HVAC system.
