Taichang's machine, if I remember correctly, should press the surf button first and then press the heating button to adjust the temperature, which has nothing to do with the water level line, as long as the water can ensure normal surfing ~

As you said, there are several reasons for problem analysis.

I didn't press the heat button.

There is something wrong with the second heating pipe.

Third, there is something wrong with the switch of the heating key. If this is the case, the switch should be flooded. Put it in a cool and ventilated place and dry it naturally. Try again.