A:Answer Pure speculation as I do not own the unit...YET... but given the units wattage and length of cord I would imagine they are using 14 AWG for their cord (they might be able to get away with 16 AWG but 14 is more likely due to liability concerns for the company). Given that, If you absolutley needed to use an extension cord, please do not use anything less than 14 guage for 25 to 50 foot cords. I always give myself extra safety room, so if it was me, go with 12 AWG for that range. I hope you would not need a 100 foot cord, but if you do nothing thinner than 12 AWG. This is not electrical advice as I am not an electrictian, use this answer at your own risk.