It's that first cold day of the year. You turn on the heat and suddenly you are hit with an odor.
What is that smell when you turn the heat on?
The answer depends on the problem. Let's talk about the most serious one first.
1. It smells like smoke. Smoke is never good. It means something is burning. If you have an oil furnace, it could mean a serious problem. Likewise if you have an electric furnace. A blocked chimney can also cause a smoky smell. Bottom line: If you smell smoke when you turn the heat on, call a professional right away for an evaluation.
2. It smells like burning plastic or burning rubber. This is also an indication of something potentially serious. If your heater has an electrical malfunction, the plastic casings on the wires could be melting. The smell could also mean an overheated furnace motor or cracked heat exchanger. Other possible causes are foreign objects like a child's toy that have fallen into the ductwork or a spill that made its way inside there. If you smell burning rubber or plastic, it's best to call a professional to find out what the problem is.
3. It smells like mold. A musty odor could mean mold is on the furnace filter, or worse, trapped in your ductwork. You should inspect your furnace filter often and change as needed. Homes with pets need to have filters changed as often as every 60 days. If changing the filter doesn't get rid of the smell, it's time to call a professional to examine the ductwork. You also need to find what caused the mold to grow in the first place and correct the issue so it doesn't grow back.
4. It smells like burning dust. Dust and dirt collect in air ducts. When you turn your
furnace on for the first time each year, this dust is burned off. This is not a big deal. The smell should go away in a few hours. If it doesn't, check your air filters to make sure they don't need to be changed. If that doesn't solve the problem, you may have a dirty heating element. If that's the case, you should call a professional for an evaluation.
Remember to trust your nose and your instincts. It's always better to call a professional and find out what's going on than to risk the safety of those inside your home.
You may want to visit our Indoor Air Quality page or our Residential HVAC page to learn more.