1, the heater water tank is broken (the probability is very small, because yours is a new car), so it needs to be replaced.
2, the water tank is blocked, you can go to the auto parts city, find a master to repair the water tank to ventilate the water tank with an air pump (there are two water pipes under the machine cover, remove them and ventilate with an air pump), around 20 yuan (it may waste some antifreeze), and go to the 4S shop at least in 200 yuan. My (Passat B5) went to Tongzhou Auto Parts City today and spent 20 yuan. It's all right now. Yesterday, I called the 4S store and they asked for 1900 yuan. I asked 1039 automobile service base, and they also asked for more than 900 yuan. I asked an experienced master. Let me share it with you. But you have to try, turn down the heating and see if there is any heating. If there is a little warm air, it will work.