All right I have to come clean......I made a very bone headed mistake. I am using 2 probes t monitor internal temp of smoker. one is the units, which I never really trusted and the other is a maverick which has worked well. when I loaded meat, I set probes in with metal clip. while I was arranging meat, I must have tugged on the wire. when I opened smoker to foil I noticed the probe shifted and stuck on the underside of the rib. Thats why temps were off.when I set it back in position it jumped high and I had to turn the smoker down from 275. Its reading well now. it reads different than the supplied probe. Im at 250 on the digital and smoker is at 230, sorry for the inconvenience you have all been a big help!