Can I Use a Heavy-Duty Extension Cord with Space Heater (What to Look For)

Most of us have a space heater around the house for one reason or another. Whether to heat a chilly bathroom, to provide extra heat in a large room, or just in case the heater goes out at a particularly bad time, they provide a burst of heat when you need it most, but most of them have relatively short cords. Can you use a heavy-duty extension cord with a space heater?

A space heater should be plugged directly into the wall if possible. If necessary, use a heavy-duty extension cord that is 14 or 12-gauge. Regular extension cords (not heavy duty) are typically 16-gauge and do not have the electrical capacity required to run a space heater. Using the wrong extension cord can lead to a fire. Similarly, power strips may overheat and catch fire if used.

Keep reading to learn more about heavy-duty extension cords, what their gauges really mean, and how to be safe when hooking your space heater up to one.

Can I use an extension cord with a space heater?

Space heaters are great to have around in the winter, but they’re also extremely when handled improperly. In fact, 88% of home heating fire deaths involve space heaters.

Now not all of these tragedies are directly related to the extension cords used to plug in a space heater – some of them will be attributable to faulty wiring that overheated directly at the outlet, and many are likely to be caused by a lack of appropriate space around the heater.

When using a space heater, consult the manufacturer’s directions. Best practices include allowing at least three feet in every direction and plugging the heater directly into the wall. However, most space heaters only have about three feet of cord, meaning that not everyone has the space required right by the wall to use the heater safely. In that case, can you use an extension cord?

Regular household extension cords can’t be used to plug in a space heater. However, if absolutely necessary, you can use a heavy-duty extension cord. Look for a 14 or 12-gauge cord.

Normally space heaters require a consistently high current supply to work. This means the extension cords can struggle to keep up with the space heater’s demands. Using the wrong cord can result in a fire.

Trying to heat a house that doesn’t have central heating? Here’s 8 tips for keeping warm!

What kind of heavy-duty extension cords can work with space heaters?

Now that we’ve established you need a heavy-duty extension cord for your space heater, what exactly does that mean?

Extension cords are basically a bundle of wires with an insulated covering and a plug at both ends. Beyond that, there are several ways that extension cords differ, the most important being:

• Length – Obviously, this is the distance from one plug to the other. Less obviously, it affects the amount of voltage lost in the transfer. For a space heater, use the shortest length that you can get away with.
• Gauge – The thickness of the wires; the larger the gauge, the smaller the wire. For a space heater, you’ll need a 14 or 12-gauge cord.
• Plugs – If your space heater has a grounding prong (the third one), then you’ll need an extension cord that matches.

Never use an extension cord that is smaller than the cord coming from the device being plugged in. Unfortunately, this doesn’t always work in reverse; even if your space heater cord looks smaller, you’ll need a heavy-duty extension cord.

Measures to take to ensure your heavy-duty cord extension works with your space heater

When choosing an extension cord for your space heater, you’ll need a 14 or 12 gauge extension cord, but you’ll also need to consult the space heater for the required amperage.

Amperage is how electricians measure the strength of the electrical current. In this case, you’ll need to find an extension cord that can handle the amperage required by your space heater.

How much amperage does a space heater user?

You’ll need to check the specifications for your specific unit, but most space heaters top out at 12.5A, so you’ll need an extension cord that can match that.

What you need to do when using the right heavy-duty extension cord with a space heater

Once you’ve got the correct extension cord for your space heater, there are still a couple of things you need to do to help protect yourself and your family.

When hooking up a space heater, you should:

• Use the right extension cord – Choose the shortest length you can get away with at least a #12 gauge and the same plug as your heater.
• Put it in the right spot – Ensure the space heater is not on the carpet. Instead, put it on a strong table towards the edge to avoid burning it.
• Allow 3 feet all around – Ensure that there is a three-foot open space around the heater. Objects left in this space will be exposed to basically non-stop heat and may combust. This is especially true of fabrics like curtains or cushions.
• Test it during the day – Allow your heater to run for the first time during the day while you can keep an eye on it. Ensure the cord is not hot, and the heater is in the right place before sleeping. 
• Pay attention to your breaker box – The breaker tripping is a warning sign that the circuit is overloaded. Even if the extension cord is correct, you could still be trying to pull too much power off the same breaker.

Read Also: Best 5 Space Heater That Won’t Trip Breaker

To avoid tripping your breaker, try hooking the heater up to a different circuit – this is different than switching outlets. Chances are good that a whole room is on the same circuit.

Alternatively, you can reduce the load on the circuit to what it can comfortably handle – as in, unplug something else so you can plug the heater in.

Never leave your space heater running when you’re not at home.

Why the use of extension cords with space heaters is highly discouraged

Even though you can use a heavy-duty extension cord with your space heater, it’s not recommended.

Most extension cords, including some heavy-duty ones, have small wiring that can’t supply the needed power the space heater requires. The wire’s length also contributes to high resistance, which results in heat on the cords. High heat accumulation is dangerous and can cause a fire.

You also need to look at the maximum amp rating of the extension cord to see if it’s compatible with your space heater. For example, if your extension cord has an amp rating of 10 and your space heaters are 12.5 amps, these two are incompatible. 

Apart from these, having extension cords with long cables in your house can lead to trips and falls.

Final thoughts on plugging a space heater into an extension cord

There’s a lot of debate on whether you can use a heavy-duty extension cord with a space heater. Some people argue that it’s not safe to use any extension cord, while others say using a heavy-duty extension cord is safe.

If you choose to use an extension cord with your space heater, make sure it’s at least #12 AWG. It should also have at least the same amperage as the heater itself, and the same kind of plug.

Also, a heavy-duty extension cord is likely to get hot, increasing the risk of fire. Regardless of the space heater’s safety ratings, amp rating, or wire gauge requirement. Remember, a thicker gauge wiring may seem safer but doesn’t guarantee you 100% safety.