New Heating and Air Conditioning units are extremely safe. Internal safety controls protect the equipment from damaging itself and they protect the home owners from certain catastrophic events. The equipment today is much safer than older equipment; however, there are dangers which the equipment cannot detect. The most severe dangers are CARBON MONOXIDE, NATURAL GAS and FIRE.
Fire is a less frequent problem than Carbon Monoxide or Natural Gas Leaks. Fire is infrequent due to safeties incorporated into furnaces. Furnaces will shut down if the temperature inside the furnace is higher than it should be. Occasionally a motor bearing will overheat and ignite wiring inside the furnace. If at any time you find smoke coming from your HVAC system call the fire department immediately. Never open a furnace compartment that is smoking or hot to the touch the compartments are often sealed and the fire will, in most cases, extinguish itself. If you are not in any danger and can shut off electrical and gas to the heating unit,do so. If there is any chance of endangering yourself call a professional and allow the professional to do their jobs.
IF YOU SMELL A STRONG NATURAL GAS SMELL LEAVE YOUR HOME AND CALL THE FIRE DEPARTMENT IMMEDIATELY. Natural Gas can leak at joints, through gas valves, and cracks in pipe. If you think you smell gas, call the fire department or the gas company. Your gas company has equipment that can detect even the smallest of leaks.