Drain, Flush and Fill

stevemac00

I need to move the 2nd floor manifold supply and return lines (3/4" hePEX) connected to distribution in crawl space.

This manifold is distributed out of a Caleffi Hydrolink 559 as shown with labels in photo. This connects to a Uponor TruFlow manifold as in second photo. The manifold supply radiant heat embedded in ceiling which is the highest point.

You'll notice there's glycol in the system which I'll ignore and re-fill with city water (unsoftened). Eventually I plan to drain and refill all zones and system.

Please help me walk thru these steps:

1. On TruFlow return mainfold: Attach hose to drain, open valve and vent. This should drain all lines in ceiling.
   
2. Attach hose to bib on return of HydroLink and drain. This should drain return line.
   
3. Drain supply line but how do I perform this? The pump has a check valve. Do I have to remove line?
   
4. Re-fill the zone. Do I refill with the same bib on the Hydrolink?