Does your furnace make a weird smell when you turn it on? This could mean you have a big problem, or it could be nothing. It is not uncommon for furnaces to emit an odor at the beginning of the season, especially if they have sat dormant for months at a time. On the other hand, certain furnace smells can indicate your system is at risk of failing, and could even pose a threat to your entire property. Keep reading to learn more about furnace smells below, and remember that for all your heating system needs, you can count on our experts at All Pro Plumbing, Heating, Air & Electric.

Top 5 Furnace Odors & What They Mean

  1. Dust: A dusty or musty smell coming from your furnace probably stems from exactly what you think—dust itself. This odor is specifically emitted when you haven’t used your furnace for a few months, and it begins to collect dust. This dust is then burned off when you turn your system on, emitting that musty odor you are now detecting. To avoid this smell, call for periodic heating maintenance.
  2. Dirty Socks: If your furnace is releasing a smell sort of like dirty socks, or that sour sweat odor you typically find in a locker room, the explanation usually goes back to bacteria. When the temperature drops in the fall, and your system’s coils cool down, the reheating process in the summer can result in condensation buildup. This ping-ponging of temperatures and condensation can result in bacteria growth. Again, proper cleaning and maintenance is the simplest way to take care of this problem.
  3. Diesel: The smell of diesel, or burning oil, can come from your furnace for a number of reasons. If you use an oil furnace specifically, that strong oil scent may be occurring because not all the oil in your system is passing through the burner, resulting in a cloud of oil fumes coming from your system. This can occur because of an oil spill or because you put too much oil in your system, or because of a mechanical issue. No matter what the explanation is, however, it’s a good idea to get it checked out by a technician if it lingers. It is also possible that your pilot light is too close to other objects in your basement, causing nearby items to melt. This is a more serious issue that will require immediate assistance. And speaking of melting…
  4. Ozone: The smell of ozone coming from your furnace is usually that of electrical burning. Similar to chlorine, you may have detected this odor before if you’ve ever been outside during a thunderstorm. It typically occurs in furnaces because the blower motor has aged, and started generating too much electricity. When this happens, it can cause wires and insulation to spark. Electrical burning is extremely dangerous, and if you ever smell it in your furnace or anywhere else in your home, call a technician immediately.
  5. Sulfur: That sulfuric, rotten egg-like smell coming from your furnace is a sign of a gas leak. Familiar to many, what you are smelling, in this case, is not natural gas itself, but the chemicals that have been added to let you know there is a gas leak. If you have a propane or gas furnace and detect this odor, turn off the system, call a technician, and leave your home. Gas leaks are extremely dangerous, and can result in fires and even explosions in a worst-case scenario.

To schedule furnace assistance today, call All Pro Plumbing, Heating, Air & Electric at (909) 253-0664, or send us a message online.