Hi, I am a relative smoking novice and have built and succesfully used a refrigerator conversion for one year. My heat source is a small hot plate-style element with an old cast iron pan for the chip pan. My current problem is that sometimes I will get a very brief run of smoke then-nothing but heat. The chunks I use are nearly all turned to charcoal. This problem is not consistent and does not seem to be dependent on type or condition of the wood. I am mostly using chunks about 1" thick. My wood is apple, cherry, and maple. Thanks for your interest and advice.