It may actually be your cord. You can use a standard non-polarized plug to test your Nano, such as one in a dvd player, gaming console, electric shaver, etc.. If the Nano heats up, usually 5 to 10 minutes, it indicates your E-Nano plug is faulty and you will need a replacement. You will not need to send back in your unit.
If your E-Nano is still not functioning, you will want to send in your unit for additional testing. To submit a warranty request email customerservice@epicvape.com or visit our SUPPORT page by CLICKING HERE