The pipe that had the leak I tried to fix a couple months ago sprang another leak like 8' away. So the plumber replaced the section of copper pipe with pex. $120 so not bad. This one looks like a valve that blew down the same pipe before it goes into the boiler
Thats y before when you had the problem I was saying do a small repair because just working on the pipe will tell you what kinda shape its in. I figure if its bad either a joint or a soft spot it'll break loose from the rattling and wiggling shortly there after if not during the work