Good evening, friends, I have a kettle and thermos at the same time Sindelen brand model HA-3500, for 6 months, it is very good but it has started to fail since now at the time of boiling the water only heats it and stops, he failed to know why he did not get to the point of boiling the water completely. I appreciate your opinions of possible problems or suggest replacing any component that is failing. Atte JRV