Natural gas doesn’t actually have an odor, which can make it difficult to detect. That is why gas companies will often add a chemical known as mercaptan, which is responsible for the sulfur or rotten egg smell. Mercaptan acts as a safety precaution that is meant to alert homeowners when there is a natural gas leak. Remember that natural gas is highly flammable and combustible, so you will want to take action immediately.

If your furnace smells like a locker room full of dirty, sweaty socks, you could have a problem with bacteria build-up on your heating coils. Throughout the changing seasons, the heating system coils repeatedly cool down and heat up, which can lead to condensation and where there is moisture, there is probably bacteria. The good news is that you can fix the problem with some elbow grease. You will want to start by changing your furnace filter and cleaning the evaporator coils. It might also be a good idea to invest in professional air duct cleaning services to completely eliminate the problem.

During the warmer months, when your furnace isn’t in use, it is natural for dust and dirt to collect. As a result, you may notice a dusty smell the first few times you fire up the furnace. This is nothing to worry about and the smell will eventually go away as the furnace burns up any residual dirt. If the smell persists, be sure to replace your filter.

Furnaces tend to be housed in basements and other damp parts of the house. Over time, this moisture may cling to the furnace. When the furnace is turned back on, it may take some time for the moisture to burn off. The smell will eventually pass and isn’t a sign of something serious that you need to worry about.

A metallic smell is an indication that a component in your furnace is overheating. Most likely, it is the blower motor, which can wear out over time and cause the furnace to use excess voltage, which will cause it to overheat. This problem can then lead to melting wires and more burning smells. Your best bet is to shut off the furnace and call a professional. Continuing to run the furnace could cause major damage and result in expensive repair bills.

Oftentimes, your nose is your best line of defense when it comes to making sure your furnace is in working order. While certain smells are normal, especially when you are turning the furnace on for the first time that season, others can be an indication of a serious problem. Don’t make the mistake of ignoring these smells and schedule furnace repair as soon as possible.