5 Best Extension Cords for Space Heaters

Erica Puisis
By Erica Puisis  • Reviewed by Ben  • Updated:   December 14, 2023
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Most homeowners dread pairing extension cords with space heaters over safety concerns.

Using the wrong extension cord for space heaters leads to overheating, electric shock, and the risk of fires. 

Top considerations when choosing an extension cord for your space heater include length, thickness, wattage, and safety features.

Here’s a list of the best extension cords for space heaters, safety, and maintenance tips: 

Top Considerations When Choosing the Best Extension Cord

The primary features to look for in an extension cord include wattage, length, cord gauge, safety features, and more. 


Wattage determines an appliance’s heat output. Space heaters usually consume 400-1500 watts. Pick a matching heavy-duty cord to prevent overheating.

Cord Gauge

The cord gauge, indicated by AWG (American Wire Gauge), determines current and heat for space heaters. AWG ranges from 10–18. Thicker wires (lower AWG) carry more current, ensuring ample heat.

Choose the cord based on AWG, not appearance, to avoid deceptive thickness and ensure safety.

Cord Length

Choose cord length based on heater-to-outlet distance, factoring in furniture turns. Avoid excessive cord length, as it may lead to voltage drop and overheating. Also, adhere to OSH regulations, limiting cord length to 100ft.

For longer distances, opt for a thicker cord (lower gauge number) to prevent voltage issues and ensure safety.

Safety Features and Certification

High-quality extension cords prioritize safety using:

  • GFCI: Guards against electric shock; third prong redirects excess current to the ground during malfunctions.
  • Circuit breaker: Halts current flow on overload detection.
  • Baby proofing: Closed outlets prevent child hazards, opening only with plug pressure.
  • Water resistance: High-density PVC resists moisture, reducing electric shock risk.
  • Indicator lights: Change colors to signal power supply or issues.
  • Certification: Underwriters Laboratories (UL) and others certify safety standards.

Top 5 Extension Cords for Space Heaters

The market is chock-full of extension cords to power up space heaters. Choosing one can be tricky, so I’ve done all the heavy lifting to help you cut through the clutter. 

Here are the top 5 best extension cords for space heaters: 

Best Overall: POWTECH Heavy Duty 12 FT Extension Cord

Our Pick
POWTECH Heavy Duty 12 FT Air Conditioner and Major Appliance Extension Cord
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Who should get the POWTECH Heavy Duty 12 FT extension cord? This is the best pick if you want a versatile, beefy, and heavy-duty extension cord to use in small spaces. 

Looking to get full value for your money? The POWTECH Heavy Duty extension cord is a solid front-runner. 

With its 14-gauge thickness, this extension cord can comfortably handle 15Amp, the standard rating for most household circuits. 

This allows you to safely plug in not only your space heater but also other appliances, including dryers and refrigerators. 

A length of 12ft makes this 14-gauge extension cord ideal for running your space heater in tight spaces.

I like that a heavy-duty PVC coat shelters the cord, protecting it against common assailants like moisture and dirt. It also enables the plug to withstand being dragged across your floor. 

Given that the extension cord is UL-certified, I feel safe using it in every part of my home. 

Plus, the cord’s grey color improves visibility, minimizing tripping hazards. 

VersatileMay overheat
Has vinyl insulation

Amazon’s Top Pick: FIRMERST 10 Feet 1875W Extension Cord 

Our Pick
FIRMERST 10 Feet 1875W Extension Cord Heavy Duty Low Profile
$13.99 $12.99
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Who is the FIRMERST 10 Feet 1875W Extension Cord designed for? This is the best bet for those looking for a safe, flat, and durable plug with a great power capacity. 

If you prefer running extension cords behind furniture for aesthetics, you’ll be impressed by the flat design of the FIRMEST 1875W plug. 

This sturdy extension cord offers up to 15Amp to serve your power-hungry space heater. 

It’s resistant to high temperatures of up to 75℃, preventing it from overheating and causing fires.

You’ll appreciate that it comes in two sizes — 10ft and 15ft. 

The flexible cord is also available in white and black, allowing you to choose an option that matches your preferences or home decor. 

Like the POWTECH cord topping our list, this cord is UL-certified, so it meets the minimum safety requirements. 

Durable construction A bit pricey
Available in two sizes 

Best Light Duty: Iron Forge Cable White Extension Cord

Our Pick
Iron Forge Cable White Extension Cord 10 Foot 3 Prong
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Who should invest in the Iron Forge Cable White Extension Cord? This is a fantastic choice for those in the market for an affordable light-duty cord that can handle abuse. 

Money is tight, but do you still need a versatile and durable extension cord? The budget-friendly Iron Forge is certainly worth buying. 

Although this thin, light-duty extension cord can only handle 13Amp, it can smoothly power your 1,500-watt space heater. 

But if you want a cord that can handle more current, consider our first two picks. 

I love that this white plug is grounded. Worrying about shocks and fires during a power surge can be gut-wrenching.  

Thankfully, this 10-foot extension cord is UL-certified. Its reinforced blades render the prongs sturdier. 

Built to lastOnly comes in white 
Has surge protection 
Suitable for multiple appliances

Best Value: US Wire and Cable

Our Pick
US Wire and Cable 74050, 50ft, Yellow, 50 Foot
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Who is the US Wire and Cable for? I recommend this extension cable if you’re hunting for a long, stylish extension cord that can withstand the test of time. 

When looking for a great blend of style, performance, and durability, opt for the US Wire and Cable. 

Besides providing such an ideal combo, this extension cord can handle up to 1875 watts and 15Amp, like the FIRMERST cord. 

Its handy length of 50ft allows for the easy placement of your space heater. 

I like that this SJTW-type cord is designed for both indoor and outdoor use since it can withstand low temperatures of up to -35°F. 

The female plug has an indicator light that lets me know whether the power is off or on. 

Visibility isn’t an issue with the extension cord’s stunning yellow color, preventing my kids and pets from stumbling. 

Power indicator light Some users dislike yellow
Durable thermoplastic jacket

Best Budget: Amazon Basics Extension Cord 

Our Pick
Amazon Basics - 3-Foot 2-Prong Indoor Rectangular Extension Cord Power Strip
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Who should buy the Amazon Basics Extension cord? It’s an excellent pick if you need a pocket-friendly option with a top-notch power capacity. 

I rarely recommend cheap extension cords for heaters, but a well-built one like the Amazon Basics is hard to miss. 

While this extension cord is only 3 feet long, it can handle up to 13Amps and 1625 watts. This allows it to power your space heater and a myriad of devices as long as they have 2-prong plugs. 

This extension cord has a flat, space-efficient design, making it a cheaper alternative to our second pick on this list. 

VersatileNot grounded

Safety Tips for Using Extension Cords with Space Heaters

Using the correct extension cord for your space heater minimizes overheating and damage.

But failure to take the following safety measures puts you, your children, and your pets at risk. 

Don’t Daisy-Chain Extension Cords

Daisy chaining or piggybacking connects extension cords until they reach the power outlet.

Piggybacking cords interfere with the voltage, resulting in overheating. The solution is to buy a longer cord to cover the distance.

Match the Extension Cord with the Right Outlet

Never remove the grounded prong from a 3-prong cord to fit a 2-prong outlet. The third prong directs electricity to the ground during a short circuit, preventing electric shock.

When dealing with a 2-prong outlet, use a suitable 2-prong plug, such as the Amazon Basics Extension Cord 2 Prong 13 Amps.

Don’t Overuse Extension Cords

Take note of the cord’s watt capacity. Whether it has a single or multiple outlets, the space heater and any other appliance plugged in shouldn’t exceed the recommended watts.

Overloading the cord results in a melted cord, your space heater could get damaged, or worse, a fire can break out. 

Protect Extension Cord from Physical Damage

Be mindful of extension cord placement to avoid accidents. Near furniture, the cord might get crushed by a chair. Passing through a door could result in smothering when it shuts accidentally.

An extension cord with exposed wires poses hazards. For example, children and pets may touch or chew on it, risking electrocution. 

To minimize risks, use a heavy-duty extension cord and place it away from furniture, doors, pets, and kids.

Final Thoughts

Choose extension cords for space heaters with the same wattage as the heater. Consider cord length and thickness (cord gauge) for efficient current flow. 

Avoid extra-long cords that reduce voltage and thin cords that can’t manage the current.

For safety, choose cords certified by recognized authorities such as Underwriters Laboratories (UL) and the International Electrotechnical Association (IEC).

Our five recommendations can handle 1625-1875 watts and have space-saving designs for convenience. 

Hey there! I am Benas, the founder and content editor at Home Caprice. Thanks for reading the article. I hope you were able to find what you were looking for. I and my team are here to simplify heating and cooling for everyone. Please have a look at the About page for more details about our website and feel free to check out our editorial process.