Smelly Furnace: Causes & Solutions

A functional, efficient, and reliable furnace is critical for a comfortable and healthy home during the cold months. Therefore, you cannot afford to have your heating system fail even for a day.

A big part of avoiding unpleasant surprises is understanding when something is wrong. And a smelly furnace is among the indicators that your furnace may fail. Learn some causes of a smelly furnace to help you take proactive measures to keep your heating system healthy.

Burning Smell

When you turn on your furnace after a long time, you may notice a faint burning smell. The smell results from burning dust that flows through the vents to your home, and you have nothing to worry about. To avoid this smell, clean the evaporator coil as the heating season approaches.

However, if the burning smell does not go away after some time, that may indicate a burning wire or overheating blowing motor. In that case, let an HVAC professional inspect your furnace immediately and fix it before more severe damage occurs.

Rotten Egg Smell

If you detect a rotten egg smell like that of sulfur in your home when the furnace is working, a natural gas leak is the most likely cause. Natural gas is colorless and odorless, but manufacturers often add an odorant to help property owners detect leaks.

Besides the rotten egg smell, you can tell you have a natural gas leak if you experience headaches, eye irritation, shortness of breath, nausea, and dizziness. If you suspect a natural gas leak, turn off the furnace immediately and call an HVAC technician to check it out.

Musty Odor

A musty smell like that of a damp basement is usually a sign of mold or mildew. Your furnace depends on air ducts for warm air distribution around your space. So, if mold grows on the vents, the mold will spread throughout your home when the heating system is running.

To avoid this situation and stop the musty smell, inspect your furnace and air ducts regularly to check for mold growth. You may need to hire a professional HVAC technician to clean and treat the ducts regularly before the heating season starts.

Smokey Smell

Smoke may signify an issue beyond the furnace. For example, the smell may mean that you have a blocked chimney, whereby smoke from the furnace cannot escape via the chimney. Instead, the smoke is forced to go through the ducts and vents of your home.

If you find a smokey smell coming out of the furnace, shut off the heating system and inspect its connections to the chimney.

Decomposing Animal Smell

A dead animal smell may mean just that. Pests, such as rodents, may enter the furnace through ventilation and leave feces and urine in the system. The pests may also die and start to decompose inside your furnace.

The only way to find out if you have rodents in your heating system is to let an HVAC professional inspect your furnace. The technician will clean and remove any dead animals to restore your indoor air quality.

A smelly furnace may indicate several problems, from non-threatening dust to dangerous natural gas leaks. The best way to protect your home and health is to inspect and maintain your furnace regularly and hire a professional HVAC technician if anything smells off.

You can trust us at Haskins Heating & Cooling for any furnace repair issues. We have a team of knowledgeable and experienced technicians who can help you get your furnace running smoothly and safely again. Contact us for a consultation.