Do I leave the air vent cap open or close it?  Do you leave the AutoFill(TM) open or closed?  Where should you put the expansion tank?  Do you pump into the boiler or pump out of it?  Hydro separator or closely spaced tees?  Where should you put the air separator?      In this episode, the guys have put together a few of the trickiest topics that come up often on the tech. support lines.  The questions are simple, the answers are more complex.  Dan and Greg will help put the questions into context, so you can understand yes, no or maybe for each project you work with.  Listen in to see where they agree or disagree.  Will this episode ruin a longstanding friendship or can the guys keep it professional?       Want to hear YOUR QUESTION on Ask Caleffi, take this quick 4 question survey for your chance to hear your question in a future episode. Survey: https://forms.gle/fRfnU8Px3B1Lq7K69