I agree with LonzinomakerCS's guess, but I have a 066 with a separate probe readout on the display. If my probe is not connected, it says "no probe." This just reverts to cooking by time. Don't know if the 025 has something similar. I do note the 025 manual is silent on this display readout. Wish I could be of more help. I'd encourage you to try CS customer service again.