Electric kettle repair, incorrect temp sensor readout

[arabianights]

greetings

I've got a Chefman branded electric kettle (Chefman-Rj11-17) that went haywire -
the kettle can be turned on normally, and the small LED on the handle displays water temperature, however, during the heating process, the temp displayed jumps to 212F rapidly, and the kettle turned off automatically while the water is still lurk warm.

I took apart the kettle and it seems that there's a little nipple at the bottom of kettle to be a temp sensor and hooked up with circuitry in the handle, but i'm not sure which part gone bad

https://www.manualslib.com/manual/2729451/Chefman-Rj11-17-Tcti.html?page=9#manual

any advice?

 

[256bits]

There is corrosion of the circuit board, second picture, near the screws and components.
Try to clean that carefully, and hopefully that ( surface corrosion ) was the cause of the problem.