A heat pump makes a loud buzzing noise when switching between heating and cooling because the reversing valve cycles the system back to AC mode while strip heaters run. Visible steam and a burning smell at the outdoor unit during this transition are normal and not a fire hazard.
That's why you hear that big noise of. Big noise of. Because reversing valve switching directions is going. So it's actually going back to AC mode. But then the strip heaters are turned on so you don't get cold in the house. But you look outside, you see steam. If your strip heater hadn't run in a long time, you probably smell like a burning smell. And then you look outside and see the steam coming from the unit, you're like, I think it's on fire. I think it's something on fire. When it's just normal operations.
How to Prevent Mold and Odor in Your Air Conditioning System with UV Light #shorts
