I’ve tested and verified that there isn’t a gap between the two by following this process:
Tighten the heat break all the way.
Tighten the nozzle all the way.
Loosen the heat break partially.
Verify that the nozzle is now able to be tightened further.
If the nozzle goes in further after loosening the heat break, this confirms there is no gap; however, if either nozzle or heat break isn’t perfectly flat, it could theoretically leave a tiny space. I don’t know if this is a common issue, but I’ve tried with multiple heat breaks and nozzles, so I don’t think this is it.
Stupid question, but there isn’t any kind of “gasket” that is meant to go between the nozzle and heat break is there? I can’t shake the feeling this spot is the cause of my concerns.