I am testing out my new brewery. I have been having issues with the burners not burning cleanly. After having to wait for pressure to build or my BK, it finely lit and was burning cleanly for about an hour with nice blue flames and the heat shield was glowing red. I turned it down to do some work underneath the stand, and when I turned it back up it was burning yellow. I could not get it to go back to the nice blue flames again. My HLT was burning yellow as well earlier. I am thinking about plugging some of the burner tips (https://www.homebrewtalk.com/f11/taming-wild-beast-multi-jet-burner-mod-52154/) but I am perplexed as to why it was working great until I turned it down.