"I got my HB FTSs system and there were no directions on how to plumb the coils. Oh and there seems to be an extra thermowell also"
Yeah - sorry about that... In our mad scramble to get parts out, we didn't do the docs yet. But SUPER EASY.
First off - YES there is an extra thermowell. it is part of the base kit and we just didn't want to rip all the boxes open to yank them out - so merry Christmas you get a free 100 mm long weld less thermowell for whatever project you like! ;)
On the plumbing, please follow this diagram here on how to best do that. Super easy!
Oh ... and here are two pics that Jens just sent into us showing how he did his plumbing (and insulation). Very slick!!