Space Heater Smells Like Burning? When It Is Normal and When to Unplug It

A short dusty burning smell the first time you run a space heater is normal. It is dust burning off the heating element and should fade within an hour. A smell of hot plastic, melting wires or fish, any smoke, or a plug that is hot to the touch is not normal. Unplug the heater and stop using it.

Every fall the same thing happens. You pull the heater out of the closet, turn it on and the room smells like burning. Most of the time it is nothing. Sometimes it is the first sign of a real problem. This guide shows you how to tell the two apart and what to do for each.

Why does my space heater smell like burning?

The most common reason is simple. During months in storage, a thin layer of dust settles on the heating element or the coils. When the heater warms up, the dust burns off and gives a dry, dusty, slightly toasty smell. Local fire officials say this is not unusual the first time a heater runs or after a long break, and they advise people not to panic over it.

Other causes include:

• New heater smell. Oils or coatings left from manufacturing burn off the first few times.
• Dust in the fan or vents. Common on fan-forced and ceramic models.
• Something too close to it. A rug, curtain, blanket or pet bed near the heater can get hot.
• A worn cord, plug or outlet. This one is dangerous.
• A failing internal part. Overheating wiring or a faulty element can smell like burning plastic.

Normal burning smell or dangerous smell?

What to do when your space heater smells like burning

1. Turn it off and unplug it. Pull from the plug, not the cord. If the plug is hot, use a dry cloth.
2. Let it cool completely. This takes 15 to 30 minutes.
3. Open a window to clear the smell.
4. Look at the heater. Check the cord, plug, vents, grille and the wall outlet for brown or black marks, melted plastic or a bent prong.
5. Check what is near it. Anything flammable within three feet needs to move.
6. Clean off the dust. Use a vacuum with a brush attachment on the vents and grille while the heater is unplugged and cold.
7. Test again on the lowest setting. Stay in the room and watch for the smell, smoke or heat.

If the smell returns and it is not just light dust, stop using it.

How long should a dusty smell last?

One HVAC contractor quoted in a local news story said the smell should last one or maybe two cycles, and if it persists you need to have it looked at. A cycle is one period of the heater running before it turns off. If it has been over an hour of use, or several days, and the smell is still there, treat it as a fault.

Is the wall outlet the problem?

Sometimes the heater is fine and the outlet is the issue. Space heaters pull a lot of power, and an old or loose outlet can overheat. Signs include:

• A warm or discolored outlet cover
• A buzzing or crackling sound
• A plug that does not fit tightly
• A breaker that trips often

If the breaker keeps tripping, read space heater keeps tripping the breaker. If the outlet itself is warm or scorched, stop using it and call an electrician.

Safety rules that prevent most heater fires

Fire departments repeat the same advice:

• Keep anything that burns at least three feet away. That includes curtains, bedding, furniture, paper, children and pets.
• Plug it straight into the wall. Not into an extension cord or a power strip.
• Turn it off when you leave the room or go to sleep.
• Use a heater with tip-over protection and automatic shutoff, especially if it is an older one.
• Place it on a flat, hard floor. Never on a rug or furniture.
• Never use an oven or gas stove to heat the home.
• Test your smoke alarms and your carbon monoxide alarm. See carbon monoxide detector beeping if yours is making noise.

Is the heater the right size?

A heater that runs flat out all day is more likely to overheat. Match the heater to the room with the heater sizing calculator, and see what it will cost to run in how much does a space heater cost to run or with the this running-cost estimator](/tools/space-heater-cost-calculator).

If one room is always cold, the real problem may be drafts or poor insulation. Try tracking down air leaks before you buy a second heater.

When to replace the heater

• The cord is frayed, cracked or hot.
• The plug has burn marks or a loose fit.
• The smell comes back each time you use it.
• It has no tip-over switch or no overheat shutoff.
• It is over ten years old and has been repaired.

A new heater with the safety features costs little compared to a fire. Look for a safety certification mark on the box, and follow the manual.

What not to do

• Do not keep using it because it "mostly works."
• Do not cover it to hold in heat.
• Do not use a heater with a damaged cord, even with tape.
• Do not spray water or cleaner inside the heater.
• Do not open the case yourself unless you are qualified.

Bottom line

A dusty smell on first use is normal and short. A smell of plastic, electrical parts or fish, smoke, or a hot plug is not. Unplug the heater, check the cord and outlet, and replace the heater if the smell comes back.