My roster was acting up and the temperature shoot up much higher than the set temperature. After communicating with Gene Cafe, it was determined that one of the temperature censors is bad. I got the replacement part fairly quickly. I put it into the machine. The roaster worked fine for most of the roasting process until the last two minutes when the temperature shoot up to over 900 degrees. I had to unplug the machine for force it cool down. The machine was sent back for repair. I would assume that the problem is something else other than the censor.