Just to clear up any confusion, the NRV (which is part of the isol valve) just has a arrow on it, IF its installed next to the (closed) isol valve thats teed into that vertical (dirty) copper pipe below, and if this vertical copper pipe is part of the system then with both isol valves closed and if you remove the hose at any end and reopen the above isol valve then no water should come out. If it has a arrow, it should be pointing into the copper pipe.
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