As the weather turns colder, many of us are starting to use our furnaces again. While a smell when you first turn on your furnace is normal, if a smell persists for weeks or even months, it could indicate a potentially dangerous problem. Exhaust fumes and gasses can be potentially harmful, so it is important to investigate any strange smells and be aware of the common causes of an odor.

Metallic Smells:

A smell of metal is usually an indication that there is a malfunctioning or failed electrical component. This issue could be a minor problem, but it is not likely to resolve itself, so you should consult a professional HVAC company or technician to check your system as quickly as possible. A prompt response to noticing this smell could help to prevent further damage to your system and reduce the risk of a breakdown.

Musty Smells:

A smell of mildew or mustiness coming from the furnace or vents is likely to be caused by a growth of fungi. This can occur in areas of moisture that have built up within the furnace or ductwork. Breathing in mold or mildew spores can have detrimental health effects, so it is important to test for the presence of mild, using a reliable home kit or by consulting an HVAC technician. Once the mold has been located, you will need to take the appropriate measures to remove it and take preventative action to avoid moisture build up in the future. If ductwork appears to be the source of the smell, you may require a professional technician to clean the ducting. You will need to close off all the vents to prevent any accumulation of debris from being dispersed around your home. The technician will also advise you about which chemicals need to be used and if there are any precautionary measures you will need to take before turning the furnace back on.

Smell of Burning:

A burning smell is usually normal as it results from any settled debris or dust on the furnace coils being burnt off when the system heats up. If your furnace is new, the smell could be the result of a coating that is applied to the coils to prevent corrosion and rust. This coating can smell a little burnt when the system is used for the first time. If your furnace is older and the smell persists for more than a couple of days, it could indicate a more serious problem. If you have noticed the smell for more than a day or two, it requires attention from a professional HVAC technician.

Rotten Eggs:

The smell of rotten eggs is often an indication of natural gas. This type of smell in your home could indicate that you have a gas leak somewhere in your system. Since natural gas does not have an odor, utility companies add a chemical to create this smell and allow homeowners to quickly detect a leak. Even a small leak can be very dangerous, so you should leave the property immediately and contact your utility company or the fire department. The smell could also be a result of a sewer pipe break or dry drain trap, which would need to be addressed if the utility company cannot find a natural gas leak.