Fix My Keurig

I have a Keurig K900. It's not very old and I was doing the first descale procedure. I didn't know what I was doing since this was the first time, so I followed the advice on a RUclips video. They said to push the brew button every time it flashed and to refill the reservoir when the add water light flashed. Mine never did. It over heated. I refused to believe that it was totally ruined. I took the cover off and looked for a device that would shut it down if it over heated.