Happy to find this forum. Just bought a 1250 yesterday. Started today at 400 for an hour just like they recommend. Shut it down after that. Then wanted to see how it works at low temps. Set at 225 and then backed down to the low setting after the temp got to 280 and continued to climb. Has been on for 3 hours now at low setting and is running at 370 and continues to slowly rise. I have not been opening the lid. The cadence that the fan cuts on has not changed, it cuts on every few seconds. Do I have a faulty computer?