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My Heater Smells: What’s Going On?

a light colored living room where the heater is blowing smelly air

If your heater has started smelling, all sorts of things could be going on. It could range from a simple issue to a more severe problem. It might mean that your heater needs a tune-up, or it could be something larger like a cracked heat exchanger.

Common heater odors include a burnt dust smell, a musty smell, an oily smell and an electrical burning smell.

If It’s a Burnt Dust Smell

This is one of the most common smells that homeowners notice coming from their heater. It often happens the first cold day or night of the season, when you turn on your furnace after it’s been off for a while.

What causes the smell is usually the burning of dust that has settled on the heater. It typically wears off after the furnace runs for a few hours and the dust has burned off. However, if the smell doesn’t go away, then something else might be causing the problem, such as a dirty air filter. Check your air filter and make sure there’s no buildup of dust or debris. If it is, changing your filter should do the trick. Or, if you have a reusable filter, clean it and you should be good to go.

If It’s a Musty Smell

Like a burnt dust smell, a musty smell typically also comes from your heater sitting unused for a long period of time. In addition to dust settling on your heating element, dust and dirt can also settle in the air ducts.

The smell should dissipate after you run your furnace for a little while. If you continue to smell something musty, then, as we already mentioned, you might need to change out or clean your air filter—depending on the filter type. A continuous musty scent from your system could mean that there is mold trapped on your filter.

If It’s an Oily Smell

In most cases, the smell of burning oil can be fixed by having your oil filter changed on your heater. But, this can also be a sign of a significant issue. Contact an experienced heating professional if you detect an oily smell. A licensed technician can help assess the root cause of the smell and make any needed repairs.

If It’s an Electrical Burning Smell

A wide variety of issues can cause your heater to smell like burnt electrical or plastic parts. One possible cause is that a foreign object has fallen into your heating system. A more serious cause could be defective electrical wiring, an overheated blower motor or another damaged part.

Some of the more typical causes of a smelly heater, such as dust on the furnace, are often easy to avoid through routine maintenance of your system. However, if you smell something like burning oil or burnt electrical parts, it’s usually best to contact a professional sooner rather than later.

While there is sometimes an easy fix for some of these kinds of heater smells, they can also indicate serious problems. These serious problems can cause significant damage to your home and can lead to costly problems if not fixed. This is why it’s usually best to reach out to a licensed heating and cooling specialist. A specialist can inspect your system, diagnose what’s wrong, fix anything wrong with your heater and help keep you and your family out of harm’s way.

If your heater has an electrical burning smell or a strong odor that’s like formaldehyde, this could mean your heat exchanger has cracked.

a white kitchen with granite countertops

Cracked Heat Exchanger Symptoms

The heat exchanger is the part of the furnace that heats air flowing through the system. If this component is cracked, it’s a serious problem that can be dangerous if you don’t work quickly to resolve it. If you smell burning electrical parts, it is important to contact a specialist promptly instead of trying to handle the problem on your own.

A pro can inspect your system, determine the problem and make all needed repairs. A pro can also replace your furnace or heat exchanger if needed. When you contact a heating and cooling specialist, some of the signs that they will look for to determine whether a cracked heat exchanger is causing the electrical burning smell in your home include:

  • Atypical flame appearance. One of the first things that a heating professional will usually check is how your furnace’s flame looks. Gas heaters usually have a steady blue flame. If the flame is another color, it flickers or it leans, then this might be a sign that either your burner is dirty or that you have a cracked heat exchanger.
  • Water near the furnace. A specialist will also look to see if there’s water on the floor near your heater. Although this could come from a condensation issue, it could also indicate a problem with your heat exchanger.
  • A buildup of soot. If a blackish substance has started to build up on the interior of your furnace, then this is often a sign that the combustion process isn’t completing and your unit isn’t burning cleanly. While this can happen when your burner isn’t adjusted properly, it can also be a sign that your heat exchanger is cracked.
  • Damage to other components of your heating system. Each time your furnace turns on, it causes some stress on the components of your heating system. This is just typical wear and tear that all units experience. But, when the internal components are not working properly, this can cause extra stress on the external components. This is why corroded or cracked external components can be a sign that something is going wrong on the inside of your furnace.
  • Physical symptoms in household members. A cracked heat exchanger can lead to leaks of dangerous gases, such as nitrogen dioxide, carbon monoxide and sulfur dioxide. These gases can make your family seriously ill. Symptoms will typically flare up while they’re at home and get better when they leave the house. Common symptoms of exposure include frequent headaches, sleepiness, nose irritation, nausea, disorientation and eye irritation.

There are many reasons to contact a specialist if you’re experiencing a burning smell. A specialist can fix problems with your heater, and make sure that you and your family stay healthy and comfortable.

Unfortunately, an electrical burning smell isn’t the only smell that could mean you have a larger problem on your hands. If your heater has a musty smell, then this might indicate the presence of mold or mildew in your furnace or ductwork.

an air vent that is blowing out musty air because there is mold in the furnace

What To Do About Mold in Your Furnace

Once mildew or mold are in the furnace or ducts, this can quickly create serious problems throughout your home. And, this problem can pose a significant risk to your family’s health. Exposure to mold can cause health issues, such as respiratory problems and allergic reactions.

Mold spores can come into a house from a problem inside the system or from outside your home. For example, water leaks and flooding are some common causes of mold growth. Inside a home, mold growth commonly happens when the ducts in a house are dirty. This dirt and dust provide an avenue for moisture to build up. Other causes of mold in heating systems include poor ventilation, condensation and humidity.

The best way to avoid mold issues is to take measures to prevent mold build up in the first place. An easy way to do this is to sign up for regular maintenance of your heating and cooling system. A licensed specialist can make sure your ducts and furnace are free of mold and any substances like dirt and dust. These professionals can also check the other components, such as air filters, range hoods, vents, condensate lines, exhaust fans and drain pans. All these parts, and others, are essential to keeping your system in good working order.

In addition to routine maintenance, to prevent mold growth you might also consider purchasing a dehumidifier. Dehumidifiers can provide added protection against mold by reducing the humidity levels in your home. This can be especially helpful for houses in more humid climates. It can also be helpful in areas of the house like the bathroom or laundry room.

If the problem seems contained to certain areas of your home, then a portable dehumidifier might do the trick. For larger issues, it might be necessary to have a professional install a device like an ultraviolet air cleaner or a whole-home dehumidifier. These systems work directly with your heating and cooling system. A specialist can determine what will be the best solution for your home and your needs.

A licensed specialist can provide you with resources on how to help prevent the mold contamination from spreading to other areas of your home. They can also perform the routine heating maintenance that’s needed to help prevent future mold growth in your system.

ABC Can Diagnose Heater Smells and Make Needed Repairs

With something large, like your heater, it can be alarming when strange smells are coming from your system. ABC Home & Commercial Services can help. Our professionals have the training and expertise to get to the bottom of your problem. Then, we can make all needed repairs to your heater. We also offer ongoing heating and cooling maintenance to make any needed fixes before they turn into bigger problems.

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