With regard to the sky: that sort of thing is inherent in the compression of jpg compression and is usually "underneath" any threshold of visibility -- but in this case I ENHANCED it rather than suppressed it. I like the way it almost looks like convection distortion above the radiator. I'm sorry if it seems off but it was a deliberate inclusion.
It's a "creative choice" I made to wildly enhance the blue contrast in the photo to pull it out. I discovered that look by accident when I "went too far" with an adjustment, but I liked what it looked like and went with it.
Sometimes, a "flaw" in an image can be exploited -- and sometimes it simply can't, lol. But we have the tools to support our choice either way and that's a good thing!