If you notice a strange odor every time you turn your furnace on, this could be a sign that you are having issues with your heating, ventilation and air conditioning (HVAC) system. Here are common furnace smells, what causes them and how to address the issue.

Burning Smell

Your heating system is made up of many parts, all of which have the possibility to wear out and get overheated. The smell of burning plastic can be a sign of wire damage or loose connections. A burning rubber or metal odor can indicate that a mechanical piece has malfunctioned. As these pieces continue to heat up, you run the risk of further damaging your furnace or worse, causing a fire. If you smell burning parts, turn the system off and schedule an inspection with a professional who can replace the necessary items.

Chemical Smell

The smell of chemicals can lead to serious health and safety issues. If your furnace is giving off a scent similar to formaldehyde (a pickle-like odor), it may have a cracked heater exchanger. When this piece breaks, gas from the furnace begins to mix with blowing air. This not only can fill your home with toxic carbon monoxide, but it can also cause a fire. If you smell formaldehyde, shut off your system immediately and call a professional to safely inspect the heat exchanger.

Rotten Smell

It may seem unusual to smell rotten eggs coming from your furnace, but this unpleasant odor actually indicates a natural gas leak. Although natural gas is odorless, gas companies add a chemical called mercaptan to it so homeowners can detect when gas is leaking. Due to the health hazards of inhaling natural gas, you should turn off your system immediately and open the windows to ventilate the air. Call a professional to repair your furnace before turning it back on.

Musty Smell

A musty smelling furnace is completely normal, especially when turning it on for the first time in months. As your heating system sits idle, dust, dirt and other debris will build up. Once your furnace warms up again, the residue will burn away causing a musty odor. If the smell persists longer than a few days you may have a clogged filter that needs cleaning. Schedule an annual inspection to ensure all parts are clean and functional.

Your furnace can produce many different smells, some that are harmless and some that require immediate attention. Now that you know what scents to be aware of, you can be better prepared in making sure your home is safe and healthy. If your furnace is due for an inspection or repairs, give Reader Heating and Cooling a call at (216) 451-1355.