14 Space Heater Safety Errors That Could Lead to a House Fire

According to the National Fire Protection Association, nearly half of all home heating fires occur between December and February. Surprisingly, fireplaces are not the leading cause of these fires. Between 2018 and 2022, space heaters and heating stoves were responsible for 46 percent of heating-related fires and 76 percent of heating-related deaths.

Space heaters can be an essential part of your home heating strategy, but safety must be a top priority to minimize the risk of fire. To avoid a disaster, it’s crucial to be aware of the most common and costly mistakes people make with portable heaters—and to avoid making them yourself.

1. DON’T crowd your space heater.

Make sure your space heater has plenty of space around it, especially when it comes to textiles. Space heaters and fabrics are a dangerous combination. “Keep your space heater at least 3 to 5 feet away from any fabric items such as furniture, bedding, curtains, rugs or anything flammable,” says Todd Tripp, general contractor and home improvement expert with JustAnswer. In fact, most space heater fires are caused by fabrics such as clothing, upholstered furniture, or even mattresses coming into contact with or being placed too close to the heater.

2. DON’T place the heater on furniture.

Never place your space heater on top of a piece of furniture, such as a dresser or table. A bump from a person or pet could knock the heater to the floor, creating a burn hazard or starting a fire. “Space heaters should not be placed on furniture or countertops, even if your countertop is a flat surface. That placement could pose a variety of risks to your home,” says Mollie Treloar, heating expert at Tractor Supply. Furniture or countertops may not be heat-resistant, and placing the heater on them could damage the surface. “Additionally, elevated surfaces like furniture or countertops often offer more restricted airflow than the floor does, which may lead to overheating,” Treloar adds.

3. DON’T put the heater on a carpet or area rug.

Your space heater should always sit on the floor, but only on a hard surface. Never place it on a carpet or area rug, as they can trap heat and may catch fire if they get too hot. “Having carpeted floors can make using a space heater tricky, but that doesn’t mean it’s not possible,” Treloar says. “If you don’t have any hard surface flooring, then placing your heater on a stable, non-flammable surface is the best bet for safety. This could be ceramic tiles or a heat-resistant mat. Just make sure the surface is bigger than the heater’s base, and set it on a level spot to prevent tipping.”

4. And NEVER run cords under the rug.

It might seem like a convenient way to keep the cord out of sight, but running a space heater’s cord under a rug is a major fire risk. When the rug covers the cord, it traps heat, which can cause the cord to overheat. This could lead to a fire. Plus, the rug could cause wear and tear on the cord over time, leading to potential malfunction or sparks. “The rug covering the cord can trap any heat generated by the cord during use and increase risk of overheating and fires,” Treloar says. “The rug fibers can also cause damage to the cord over time and lead to malfunction and spark risk. Also, the cord covered by the rug can pose a major trip hazard to your family and pets as they would not be able to see it while walking.”

5. DON’T use an extension cord.

Avoid using extension cords or power strips to plug in a space heater. Space heaters require a high amount of power, which can overload an extension cord or power strip, causing them to short-circuit or overheat, leading to a potential fire. Always plug your space heater directly into a wall outlet, and refrain from plugging other devices into the same outlet while the heater is running.

6. DON’T leave pets or kids in the room unattended.

Space heaters might be inviting to pets, especially cats, but leaving your furry friend unattended near one is risky. The warmth from the heater may attract them, but you should always turn the heater off when you leave the room. The same rule applies to young children—never leave them alone with a space heater running.

7. DON’T expose the heater to moisture.

It’s tempting to use a space heater in the bathroom to warm up while you shower, but doing so could be dangerous. “Because of a bathroom’s increased humidity and proximity to water, you have to take extra precautions with your space heater,” Treloar says. “Take care to use a model specifically designed for the bathroom, and make sure you place your heater far enough away from your sink, shower, or bathtub to eliminate the risk of water damage or splashing.”

8. DON’T run a space heater overnight.

Never leave a space heater running overnight while you sleep. If the unit overheats, tips over, or malfunctions, it could start a fire while you’re asleep. “Space heaters need to be respected as a highly flammable appliance,” Tripp says. Use the heater to warm up your room before bed, and turn it off before you go to sleep.

9. DON’T forget to check for certification.

Before purchasing a space heater, make sure it’s certified by a recognized safety organization. “Space heaters with a UL (Underwriters Laboratory), CSA (Canadian Standards Association), and ETL (Intertek) should only be used,” Tripp says. “Space heaters with one of these certifications have been tested and approved for safety electrically and fire hazards.” The certification will typically be marked on the packaging or the unit itself.

10. DON’T use a secondhand space heater.

While secondhand items can be a good bargain for some household goods, space heaters are not one of them. “Using secondhand space heaters can be risky,” warns Treloar. The certification sticker might be missing or have never existed, the wiring could be damaged, or internal components might be faulty. Plus, it’s hard to tell the age of a secondhand heater. Using an old or damaged heater can be a recipe for disaster.

11. DON’T continue using a space heater when it’s old or damaged.

Even if a space heater has built-in safety features, such as an auto-shutoff if it overheats or tips over, older models might lack these protections. “If it’s over 10 years old, it may lack modern safety features and efficiency,” Treloar says. Signs that your heater is wearing out include taking longer to warm a room or not heating as effectively as before. “Any strange sounds, such as rattling or buzzing, or unusual smells, like burning or electrical odors, are immediate red flags. These could indicate internal damage or potential fire hazards. Also, any signs of physical damage, such as cracks in the casing, frayed cords, or scorch marks. These are clear indicators that the heater is no longer safe to use and should be replaced,” she says.

12. NEVER put the space heater in front of a doorway or egress point.

In case of an emergency, never place your space heater in front of a doorway or any exit path. Blocked paths can be hazardous, especially in the event of a fire or other emergency. Always ensure your heater is placed a few feet away from any high-traffic areas or entryways to avoid accidents.

13. DON’T put things on top of your space heater.

It may seem convenient to dry wet items like mittens on top of your heater, but that’s a dangerous practice. “Space heaters are designed to heat spaces, not to dry clothing, and using them for this purpose can pose significant safety risks,” Treloar says. “Clothing that is placed too close to a space heater can overheat and potentially catch fire, especially draping clothing over a space heater to dry it faster. Draping can block air vents and cause the heater to overheat, increasing the likelihood of a malfunction or fire.” Similarly, never store items on top of the heater. While modern space heaters come with safety features like overheating protection, these features aren’t foolproof if the heater is being used improperly.

14. DON’T run propane space heaters without ventilation.

Non-electric space heaters, such as propane models, can release dangerous carbon monoxide. Always use these heaters in well-ventilated areas, such as on a patio, or outdoors. “You should also choose a model equipped with safety features like an oxygen depletion sensor (ODS), which shuts the heater off if oxygen levels fall too low,” Treloar adds. “Finally, when refueling, users should also take care to choose the correct fuel type for their heater and always let the space heater cool before refueling to minimize fire risk.”

By following these space heater safety tips, you’ll significantly reduce the chances of an accident and help keep your home warm and safe throughout the winter.