Explaining Five Strange Smells That Come from Your Furnace

January 6, 2022

Over time, your furnace is likely to release a few funky smells. Furnace odors are particularly common during this time of year, when you are probably at your peak heating needs. Some furnace smells are pretty harmless, while others indicate you may have a serious problem on your hands. Let us explain the smells coming from your furnace below, and remember, Winters® Home Services is available for all your emergency HVAC needs.

Rotten Eggs

A sulfuric, rotten egg-like smell coming from your furnace is a common sign you are dealing with a gas leak. Natural gas is one of the most common furnace fuels, as it is highly combustible, and extremely energy-efficient. However, when something goes wrong in your system, and gas starts to leak out, the results can be extremely dangerous. Watch out for other signs of a gas leak such as headaches, nausea, dizziness and fatigue, and remember to get your family out of your house ASAP if you detect this smell in your home. It is also key to avoid using anything flammable when you detect a gas leak, as this could – in a worst-case scenario – cause your whole house to go up in flames.

Dirty Socks

We’ve all detected that dirty sock smell when entering a locker room before. This is the smell of excess moisture, and the bacteria that goes with it. You may smell this odor coming from your system when moisture starts to build up on the coils. This often happens when the thermostat is frequently turned up and down. If you are picking up a dirty sock smell coming from your furnace, make sure to call a technician for a cleaning right away.

Diesel Fuel

If you are smelling diesel coming from your furnace, like what might put in your car, it’s probably because there is too much oil in your system. Oil is another stable fuel source for furnaces, but when there is too much oil in your system, it may create a cloud that becomes highly flammable when it interacts with your heating element. Next time you are putting fuel in your oil-based furnace, make sure you are not using too much, and always call a technician if you detect this smell. Too much oil may cause your system to overheat, making it a potential fire hazard to objects around it.

Electrical Fumes

Most people have probably smelled the electrical fumes that come with burnt wires before. You may recognize this smell coming out of your furnace as the blower motor ages, and starts to use more electricity. When this happens, sparking may occur in your system’s wiring and insulation. Electrical fires are something you want to avoid at all costs, so do not hesitate to call a heating technician immediately if this smell comes wafting from your furnace. Failing to do so may require you to pay for extensive repairs, if not a complete replacement.

Must & Mildew

When your furnace sits for months without being used, it is only natural for the unit to collect a good amount of dust and debris. When this dust starts to burn off, you may detect a musty odor in your home. Luckily, this odor doesn’t usually indicate there is anything severely wrong with your system. You may want to reduce this nasty smell, however, by replacing your furnace’s filter at the top of the winter season, and calling for maintenance annually. This will improve your system’s performance and strengthen your indoor air quality.

Contact Winters® Home Services now at 617-221-5899 to schedule furnace service, or send us a message online.