I trying to finish installing a Central Boiler wood fired heating unit.
Visit their website:

I am concerned about what will happen when the hot water moves through the insulated underground PEX line to the hard copper connection in the basement to the hot water tank & heat exchanger in the forced air furnace.

My questions are:
1. Do I need a flexible copper fitting where these lines connect at the transition?
2. Should I use a copper "Fast/Flex" connector as manufactured by Slant/Fin, Greenvale, N.Y. 11546 Phone 516-484-2600?
There is nothing on their website http://www.slantfin.com/contact.html
3. Is there another product available which gives the same flexible transition from hard copper to plastic PEX pipe?

Thank you for any advice!

Jerry Gibbons
Dowling, MI