Sounds like they mightn't have seen
@Vapor_Eyes GH fixes resource. This might be a good thing to bring to HL's attention as it covers a lot of tweaks and progression we've discovered over the years
Edit: great minds think alike, thought I may as well leave this a short post after seeing your near simultaneous thinking Joe
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The difference seems to be a dodgy back-end stays dodgy, no matter what you do. Cleaning it, twisting it, makes no difference, it just stays a bit shit regardless.
It's not so much the heat that's a problem, that seems more random than anything. A proper dodgy back-end simply prevents proper vaporisation. The clouds are thin and the ABV is not as deplete, the red light lingers much longer, and that remains constant.
My good back-end heats up from time to time, just like my dodgy/warranty replaced back-end.
But the difference is notable and unmistakeable, even without comparison. The dodgy back-end prevents the hopper from working, heat isn't a good indication of a broken back-end. If it's still pumping out big clouds, it's all good. It's easier to notice the weaker production when using through glass also.