This unit worked very well for 2 months.The temperature fluctuates a bit, +- .4 degrees, during cooking time but that is not a problem.The last few times, the temperature of the water never reaches the set temperature. Set it to 150 and it never passes 144.8. It goes back to 144.6 and then back to 144.8 and repeats non-stop.When the water temperature displays 144.8, if you change the set temperature to 130, the water temperature display instantly goes to 129.8, then 129.6 and back to 129.8 although 5 seconds before it showed 144.8.Not usable anymore.Very disappointed. This just passed the return window.