How does a professional semi-automatic coffee machine adjust the water temperature and the steam temperature of his milk bubble?

Generally, there is no way to control the steam temperature, only to adjust the size. The high water temperature at the coffee outlet generally means that there is no exhaust at the top of the machine and there are too many things covered. In addition, if the machine does not run for a long time, the temperature of the coffee outlet will gradually increase, because the whole knot of the coffee outlet is copper, which is easy to accumulate heat. It's better to put the water for more than ten seconds when making coffee, which will be better. Once the water temperature and water pressure of the machine are found to be abnormal, it is best to find an after-sales or professional master to repair it. Although the price is expensive, it is more expensive not to pretend to know yourself.