Hi all,
My apologies for going AWOL on this. Having the pinhole leak almost seal itself (at least to the point where there wasn't perennial dripping) afforded me the opportunity to move on to other pressing projects, but fully fixing this has been on my to-do for months.
Here's where I am: The pinhole leak on the hot side has crusted over which continues to grow, while the cold side still maintains a perfect seal.
I've grown interested in the idea pitched earlier in this thread to use brass fittings on which the flex pipe would form a better seal. So, is the idea to remove and toss the old flex pipe and clean the existing sweated-in copper mpt threads with a brass brush, then thread in some sort of brass bushing combo that will allow me to thread in a male 3/4" brass nipple, using pipe dope on all of these threads? Then the flex pipe should seal much better against this? If so, would I start with a brass 3/4" FIP x 1" MIP bushing, followed by a brass 1" FIP x 3/4" FIP reducer, then a 3/4" x 3/4" brass nipple?
I also have to ask, in parts of the country where local code requires flex pipe, what's the standard way of setting this up using only threaded fittings? I ask because this flex pipe is used to often that I expect my issues to be commonplace.
Also, I'm getting significant corrosion on the cold side nipple. It started within a few weeks of install. Should I change the nipples out in favor of brass?
Finally, I also have a pinhole leak at the expansion tank:
I'm guessing this was improper, relying on teflon tape to make the seal. Any suggestions on remedying this? This one is tricky since I supported the expansion tank with a quick strap that's mounted to the wall with tap cons. So if I do a similar setup above with brass bushings, it would lower the tank to the point where I'd have to remove and reinstall the bracket. Can I just clean the threads and reinstall the tank with pipe dope?
As always, shared thoughts and expertise are deeply appreciated.