With my AmeriQue, I have found the meat temp must be 40* or better to have the unit probe register anything and go into its "probe cooking" mode even though initially set that way. With meat temp under 40*, the unit first registers "No Probe" and then starts cooking in the "time" mode but shortly after meat warms-up to 40* or above, it will then register meat temp and cook in "probe" mode without any problems. When ever I use the probe cooking feature, I just make sure there is some amount of time still set from a previous cook to get it started cooking, and everything turns out fine. The AmeriQue is a great unit, but some just have that one little below 40* quirk to it when using the probe mode.