Using extension cords with electric fireplaces We don’t recommend using them. Avoid using an extension cord because the extension cord may overheat and cause risk of fire. However, if you have to use an extension cord, the cord must be Number 14 AWG minimum size and rated not less than 1875 Watts.Click to see full answer. Simply so, can you plug an electric fireplace into a surge protector?Plug space heaters directly into a wall outlet. Do not use an extension cord or power strip, which could overheat and result in a fire. Do not plug any other electrical devices into the same outlet as the heater.Similarly, does an electric fireplace need a dedicated circuit? Most electric fireplaces can be plugged into a standard 120 Volt outlet, and no dedicated circuit is required. Additionally, can you use an extension cord with an electric heater? You should never use an extension cord to plug one of these heaters into a power source. Instead, space heaters should be plugged directly into electrical outlets, but even there you must be careful not to exceed the amperage rating of that circuit.Is it OK to leave electric fireplace on all night?Yes, it is okay to leave an electric fireplace insert on overnight but it’s best if you turn it off when possible. Although electric fireplaces do not produce any carbon monoxide fumes, its best to turn your electric fireplace off when you leave the room for an extended period of time or plan on catching some zzz’s.