Got the same problem as well. Plugged the unit on an indoor outlet and let it run for a couple of hours. Then switched back to the GFI plug and everything appears to work.
I was amazed by the amount of smoke generated by those 2 chunks of wood. Now I am ready for the real thing, that is cook meat instead of air.
How do you clean the oven. I know we want to keep it seasoned but this thing is going to be a bit messy?