I experienced the same thing. I was given the fermwrap by a friend and it had never been opened. I called Fermentap to ask how long it should take to warm up. We determined it was defective. Because it was a gift I had no receipt. However, the customer service rep was able to look up my friend's name and confirm he had purchased one. They sent a replacement free of charge (despite having no receipt to show). I have not yet used it, but have plugged it in and could feel the warmth rather quickly. I haven't used it yet as I found an old heating pad to use in the fermentation chamber while I awaited the new fermwrap. Good luck!