Is It Ever Normal to Smell a Gas Furnace Outside?

Natural Gas Smells

• In its natural state, gas actually has no distinct odor of its own. But because of the extreme danger of gas leaks and in order to aid consumers in discovering leaks, natural gas providers are required by federal and state law to add chemical compounds to natural gas so that its smell is more easily detectable. Sulfur compounds are most commonly used by gas providers, so the gas your furnace uses will most likely take on a rotten egg smell. It is normal for the area around the furnace to smell faintly of gas, but if the smell is so strong as to be detectable outside, there could be a problem.

Safety

• First, ventilate the area around the furnace by opening doors and windows. Do not use a match, lighter, candle or other open flame as a light source and do not turn on any electrical switches or light switches. Have all the inhabitants of your home leave immediately and call 911 or your gas company. Whomever is dispatched to your home will investigate if and where a gas leak is occurring and will declare when it is safe to come back inside.

Addressing the Problem

• Once the house has been cleared as safe to re-enter, the next step is to actually address the source of the gas leak. The sulfur added to gas has a very strong odor even at very low air concentrations, so even if you are smelling the gas outdoors or near the furnace, the source of the gas leak could be somewhere other than the furnace itself. The gas company can at least locate the true source of the leak and can often repair it themselves; if the gas company representatives cannot provide the repairs themselves, they can often provide recommendations for a repair service that can.

Other Smells

• If the smell your furnace is producing outside is not actually natural gas, danger to your family is less likely. A burning or dusty smell from a furnace is not uncommon when the furnace has not been used for sometime; dust built up on the furnace's combustion chamber after long periods of inactivity will be burned off once the furnace starts up again. Change the air filter if the burning smell persists and contact your gas provider if the smell does not go away eventually.