Thanks for everyone's feedback. Ruth, I also called tech support at Thermoworks and they told me the few thermometers they checked were not affected by induction cooktops. However, they have received calls from some customers mentioning this issue. Ruth, are you using a portable induction cooktop or one that's part of a range? @Gap, I think you may be on to something. Because I have way too much time on my hands I tested 3 digital thermometers on a range induction cooktop and a hot cooktop. All three showed fluctuating readings by a several degrees (210-215) on the induction cooktop and did not read 212 F in boiling water. On the hot cooktop the readings were steady and 1 of the 3 read 212.1, one read 213. and one was way off (215). The accurate one is the Thermoworks Calibration Thermometer and worked as expected on the hot cooktop. Since the other two thermometers are only accurate to within about 2 degrees, I suppose they worked as expected on the hot cooktop too. So, it appears all of my digital thermometers are affected by my induction cooktop.