I use the house in Beiding just like you. When I first started using it, I found that the machine always bubbled when it was working, thinking it was abnormal. The consultant told me that the health pot uses a U-shaped heating tube, and the heat near the heating tube is larger than that, so it is normal to see that only half of the heating plates are bubbling. Normally, the current industry technology is the same. I'm relieved. I have used it for many years without any problems. It's quite convenient.

I hope I can help you and adopt it. Thank you!