Leak in copper Line

I have a copper supply line with a leak. The line is difficult to access because it runs above an HVAC duct. I had a plumber come out and tell me that the HVAC will have to be moved and that the HVAC probably made the line leak. Well, I have LOTS of plumbing lines cross-crossing over HVAC - does it all need to be moved/replaced? Was the plumber right that the copper lines should not run on top of HVAC (note the lines don't touch the HVAC - they run about one inch above it). Thanks for any information.

The pros on this forum may have a different opinion, but I see know reason why the HVAC would have anything to do with the copper line leaking if there is no contact between the two. I also see no reason why the HVAC would have to be removed to make the repair. You may have to replace a length of pipe if the leak can not be accessed. Perhaps there is more to the story?

Hcac

The only reason to move the HVAC is if there is no other way to access or reroute the leaking line. It has nothing to do with the other lines.

You should check the pH of your water. Low pH acidic water can cause pin hole leaks in copper tubing. There are other causes too but pH is the most common.

In my area they added orthophosphate to the water to prevent pinhole leaks.

That may or may not stop pin hole leaks caused by low pH acidic water or the other things found in the water that cause them. It won't stop any electrical or erosion caused leaks.