Can a Window Air Conditioner Use an Extension Cord?

No. GE’s, Midea’s and LG’s window air conditioner manuals all say do not use an extension cord. Plug the unit straight into a grounded wall outlet, with nothing else plugged into it.

What each maker’s manual says

GE Appliances, AHD06 and AHD08 manual (2022): “DO NOT use an extension cord with this Window Air Conditioner,” and no surge protectors or multi-outlet adaptors. The unit gets its own individual outlet, a grounded 115/120 volt outlet protected by a 15 amp time-delay fuse or breaker.
Midea, EasyCool and MAW08V1YWT-S / MAW12V1YWT-S manuals: “Do not use an extension cord or an adapter plug.” Midea asks for a dedicated circuit and no other appliances on the same outlet.
LG, LW1812HR and LW2412HR manual: no extension cord in its setup steps, a dedicated circuit, and no extension cord ever on 230 or 208 volt units.

Follow the manual for your own model.

Where LG’s manual differs

In the electrical safety section of the same manual, LG says it strongly discourages an extension cord, but that if you use one anyway, it should be a UL-listed or CSA certified three-wire grounding cord rated 20 amps and 250 volts.

GE’s and Midea’s manuals give no cord rating at all. The safe choice for any window unit is the wall outlet.

The test button on the plug

The plug on GE’s AHD06 and AHD08 has a safety device with TEST and RESET buttons. Midea’s and LG’s manuals describe one on the units that have it, and Midea says it senses damage to the power cord. GE says to test it now and then: press TEST, then RESET, while it’s plugged in. If TEST doesn’t trip it or RESET won’t stay in, stop using the air conditioner and contact a qualified service technician.

No outlet near the window

Use a window that has a grounded outlet within reach of the unit’s own cord.
Or have an electrician add an outlet. Each of these manuals wants the unit on an outlet or circuit of its own.
A 230 or 208 volt unit needs a matching outlet, which is electrician work.

Never cut or remove the plug’s ground prong, and don’t use an adapter plug to fit a two-slot outlet.

Common questions

What gauge extension cord does a window air conditioner need?

GE and Midea don't list one, because their manuals say not to use an extension cord. LG's LW1812HR manual says the same, and adds that if one is used anyway it should be a three-wire grounding cord rated 20 amps and 250 volts.

Can a window air conditioner go on a power strip or surge protector?

GE's manual says not to use surge protectors or multi-outlet adaptors with its window units, and Midea's says not to share the outlet with other appliances. Plug the unit into the wall outlet itself.

Where we get our information from

The advice comes from the window air conditioner makers’ own owner’s manuals: GE Appliances, Midea and LG. Checked against published data from GE Appliances, Midea and LG.

See all 3 sources

GE Appliances, room air conditioner owner's manual, AHD06 and AHD08 (49-5000721, 2022): use of extension cords, surge protectors, the current interrupter plug, electrical requirements
Midea window air conditioner user manuals: MWA EasyCool Window (2017) and Inverter Window MAW08V1YWT-S and MAW12V1YWT-S: extension cords, adapter plugs, sharing an outlet
LG, window-type air conditioner owner's manual, LW1812HR and LW2412HR (MFL67462101): before operation, electrical data, use of extension cords

Can you plug a window air conditioner into an extension cord?