Heavy corrosion on indirect HW tank cold inlet

gmcinnes

Hi. I've seen posts about HW tank inlet corrosion, but none seem to be what I have. Apologies if this is a repeat though.

I get a ton of green corrosion on my HW tank cold inlet. No corrosion on outlet side. No leaks though and heater works perfectly. Pictures below... One as found and one after brushing off the crystals and wiping down. Is this problematic and how to fix it if so?

Some details: It's a 2017 50 gallon Triangle Tube ACV indirect heater, coming off of a fuel oil boiler. Well water, but minimal hardness and neutral pH. House is 1840, so god knows what's in the walls, but everywhere I can see is copper pipe or pex. Pipe from boiler to HW heater is copper to pex to copper.

(X-post to plumbing)

EBEBRATT-Ed

I would take it all apart and install new fittings. My guess the top propress fitting has a pinhole leak that is dripping down and corroding all the fittings

hot_rod

a source of moisture is causing the corrosion, replace and redo the connections from the copper down. The press fitting seems to be the source of the problem

HeatingHelp.com

@gmcinnes, I've merged your duplicate posts into one here to prevent confusion. Thanks.

ethicalpaul

a source of moisture is causing the corrosion, replace and redo the connections from the copper down. The press fitting seems to be the source of the problem

Agreed. Use sharkbite this time: sharkbite water heater connectors

There is less chance of installer error and they will let some movement occur without breaking stuff

gmcinnes

Thanks guys. That was my diagnosis too, given the corrosion pattern. For the sake of my pride, let me note that this was the plumber's install :)

Thanks for that link @ethicalpaul

While I was reading up on this I looked over the install/maintenance manual for the heater and I don't see any mention of an anode. Does it sound right that one might not be required?

The manual does recommend using a dielectric union. Any thoughts about that?

hot_rod

I think the stainless nipple is welded into that tank in tank indirect. The hose bib is to drain it as there is no bottom drain

The brass tee, which is reusable, is enough of a dielectric

SuperTech

Dielectric unions are notorious for being leakers. As Hot Rod said, the brass tee is all you need. I always install a threaded brass fitting on the hot and cold water connections to the tanks. I prefer to never use shark bite fittings. I see them leak fairly often. I prefer to solder. No matter what you do, cleaning and de-burring the pipe, cleaning the pipe and fitting and keeping everything straight and level is the most important thing to avoid any leaks.