4 Reasons Not to Use a 16-Gauge Extension Cord With a Space Heater

Space heaters draw 12 to 15 amps on high, but a 16-gauge cord is only rated for 10 to 13 amps. This mismatch means the cord is overloaded from the start.

Overloading causes heat buildup in the cord. As the cord gets warm, electrical resistance increases, which can melt insulation and start a fire.

Longer or older cords are even more dangerous. Resistance increases with length and wear, making heat buildup worse over time.

If you must use an extension cord, choose a 12-gauge or thicker cord rated for at least 15 amps. Keep it short and fully uncoiled, but plugging the heater directly into the wall is always safer.