I have a hot water boiler (recently replaced) that provides both DHW and heating in 3 zones. The zones are by run by floor. The basement zone piping was run through the slab when the house was built (1965). Since the piping is approaching 50 years of underground contact I want to replace the piping run to above-ground (under the basement joists like the 1st and 2nd floors).
I know my job would be easier with individual zone isolation, but am unsure if I COMPLETELY have that with the basement zone. I can see both a drain and isolation valve on the return, but am unsure as to whether I have or need an isolation valve on the source (see attached pics).
PIC1: Shouldnt there be an isolation valve on the basement zone supply?
PIC3 : I am also unsure of the extra drain bib on this line?