I had a problem with my probe (maybe) today as well. I put 13 jumbo turkey legs on between 12:30 and 1:00 p.m., placing half on the 2nd rack and the other half on the 4th rack. I put a water pan in, stuck the probe in a larger leg on the bottom shelf, and set the box temperature to 240 and the temperature to the meat at 170.
A little after 2 o'clock, I called my wife to ask her to check on how things were progressing. She said the box temperature was holding steady at 240 and the probe was indicating 130. I thought to myself there was no way the temperature could have reached that high in an 1-1.5 hours. A little after 3 my called saying the cooking cycle had concluded. I thought no way, so I told her to turn off the smoker and I would come check.
My first thought was that I did not insert the probe in fully or based on watching a youtube video recently, the density of the bone in the meat may be giving causing the temperature to misread. When I reached the house and opened the smoker, I noticed the meat was not completely done, so I emptied the water pan and replaced the water, emptied the oil pan (both were overflowing), changed the racks and re-entered the probe into one of the larger legs.
I turned the smoker back on and made sure the temperatures were still the same and monitored it for about 20 minutes. I noticed that as the box temperature went up, so did the probe (running about 10-20 degrees below the box temperature). Once the probe temperature hit 160 and the box temperature was still about 185, I figured something was wrong. So I recycled the smoker to cook at 240 while I return to finish some work at the office.
That was about 4:30 when I left. I am leaving for the day, so I will check in about 30 minutes. My probe worked perfectly last week, so I am not going to be quick to say that is the problem. Thoughts?