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Why Does Your New Furnace Smell Like Burning Plastic?

Why Does Your New Furnace Smell Like Burning Plastic?

Furnaces are a great way to keep your home warm and dry in the winter months. They have many benefits, but one of them is not the smell that it emits. If you turn on your furnace for the first time, chances are there will be an odor coming from it. It might smell like burning plastic or sulfur – either way, this is not good news. This blog post discusses why furnaces often emit these smells when they’re turned on.

1. Plastic Item Must Have Fallen Into The Heater

There are a number of reasons why your furnace may start to smell like burning plastic. In most cases, it is because something has fallen into the heating unit and needs to be removed or replaced with the appropriate part.

  • If you have recently experienced this issue, turn off the power at your home’s electrical panel before investigating.
  • Look inside the furnace’s air filter and see if you can find anything that looks like plastic. Remove it with a vacuum cleaner or broom before turning on the power again.
  • If nothing is found, remove the cover from your heating unit to examine for problems in the heater itself, such as dirt build-up around wiring or coils.
  • If you find a plastic item in the air filter and it is not from your home’s heating unit, remove all items until the smell goes away.

2. Frayed Electrical Items

In some cases, a burning smell is caused by frayed electrical items. If you notice that the odor only appears when your furnace turns on or off and not at any other time, this might be what’s causing it. Electrical items are protected from overcurrents while the power is turned off, but if one of them has been compromised in some way, the overcurrent protection can’t work.

You will usually notice this smell when they plug something in or unplug it, and a spark flies out from either place. This is most common with extension cords that have been plugged into an outlet then turned off before fully unwinding themselves. The same goes for power strips which also need to be unplugged fully before turning them off.

Also, keep in mind the age of your furnace, as these things are more common when a unit is older than ten years old. Over time, wire insulation becomes brittle and can wear away to expose bare electrical wires that short against each other – which could cause an odor while the power goes on and off. If you experience this issue, you can let a professional at Anderson Air look into the problem and get it fixed. 

3. Burning Filters

If you smell burning filters, then your filter is clogged and needs to be replaced. This might happen because of oversaturation in the furnace with air or dust particles. You should also check that there isn’t a leak somewhere on the system and call for service if necessary.

Why Does Your New Furnace Smell Like Burning Plastic?

Other Problems That Your Furnace Might Deal With

Apart from the plastic burning smell, the following are some other issues that your AC might run into:

1. Odd Noise Coming From Heater

If you’re hearing odd noises coming from your furnace, there may be an issue with it. The most common noise is a fan running loudly and more frequently than usual. This typically indicates that the motor in the system isn’t working properly or has gone bad. There are also other causes for this that will require further investigation to ensure proper maintenance.

2. Dust In the Air

The smell from your heater may be caused by dust in the air. The furnace is sucking up particles of dirt, hair, and even fabric from your carpet or furniture. If you notice this happening every time that the furnace kicks on, it’s a good idea to vacuum more often (especially around vents) and make sure there are no areas where lint can build up.

There are also ways to get rid of the smell from your furnace. Make sure you have a clean filter and replace it every one-to-two months or as needed for heavy use. You can also try opening some windows in order to ventilate the house while the furnace is on, but be careful not to let any cold air in.

3. Frequent Cycling

If your furnace is cycling on and off too frequently, this could be the source of that burning plastic smell. A thermostat might not be set high enough, or it may need to be reset for proper operation. Make sure you have a programmable thermostat installed so you can avoid unnecessary cycles during periods when no one will be home or awake.

4. Smell Of Gas

One of the first indicators that something is going wrong with your furnace is the smell of gas. You should never ignore this, as it could mean there’s an issue in the venting system which needs to be addressed immediately by a professional technician. If you can detect anything smelling like natural gas, call a professional and have them come out to check your home.

5. Pilot Light Is Yellow

The color of a pilot light is usually very bright orange, but if the light has turned yellow, it might be time for repair. A red or blue-colored flame indicates that there’s an issue with your heater and should be dealt with immediately because it can result in carbon monoxide poisoning. If you are experiencing strange smells coming from your heater, it’s best to call a professional for heater repair as soon as possible as soon as possible.

6. Weak Air Flow

If the air is not moving through your new furnace, it will start to smell like burning plastic. This can be due to a low setting on your thermostat or inadequate ventilation in the area where you have installed the unit. Normally this problem goes away after turning up the temperature and ventilating more around the system. If that doesn’t work, there may be some kind of obstruction in the vent that is causing this issue.

Do not move or turn your furnace on again until you have verified that the problem is fixed. If it smells like burning plastic when your power turns on, call an electrician to investigate the issue before continuing use of the unit.


Above are some of the common reasons why your furnace may smell unusual. If you deal with any of the aforementioned issues, make sure to get in touch with a professional immediately and resolve the issue before it becomes a health hazard.