Thread: What is the likelihood?

What is the likelihood that galvanic action would occur in this spot? It seems to me that calling this out is a little on the picky side, but what would be the fix?

Won't be a problem. The copper is isolated from the steel.

I would be more concerned with the flue pipe. It's not even close to compliant. Flex is not an allowed type B vent.

So is the copper isolated because of the PVC? If you could give me a little more info on why it's isolated that would be helpful.

The flex pipe is a Dura-vent pipe and is rated for this use (Simpson Dura-vent), but that really wasn't the question.

Because of the copper flex commectors have a plastic/nylon bushing that prevents any contact of the copper to steel.

If you look at your picture, on top of the brass nut, you can see the bushing protruding above the nut. The bushing is inside the nut and flares out so that there is no contact inside of copper to steel. The whole thing is totally isolated.

Make sense?


Is there a copper bushing between the CPVC and and steel T? If so, no it's not isolated. They should have used either a steel or CPVC bushing.

So I understand the flex pipe and should have been more specific... my question is in reference to the bushing at the CPVC. It is a Copper male fitting with the CPVC on the other side. The Copper male fitting connects to the Galvanized female just above the water heater.

The nylon bushing isolates the copper from the brass which is in contact with the galvanized.
On the inside there is (should) be a black rubber washer that isolates the copper from the galvanized.
I've seen these connections many times with and without corrosion and green patina. I think it's probably a crap shoot based on water type, washer and bushing condition.
Hope that helps.

Reis, are you certain that is copper? I've used CPVC fittings like that, and the metal half is brass (FlowGuard fittings). If so, then it's not an issue.

There is that leak coming from under the teflon tape...

yeah, the bushing on the T to the CPVC shouldn't have been copper but it is pretty minor. It could go a long time without even noticing any corrosion and then again may last forever without any problems at all.

Originally Posted by Ken Meyer

Reis, are you certain that is copper? I've used CPVC fittings like that, and the metal half is brass (FlowGuard fittings). If so, then it's not an issue.

I guess that I'm not certain that it's copper, so I will look into that and agree if it's brass we're good... I've used them myself and they've always been copper so I just assumed it was copper (that and the coloration). The reason I was drawn to it is for the corrosion running down the galv line (Richard - it was not an active leak, but I felt like it was a sign of a past one). I don't mean to pound this in to the ground, but I called the copper/galvanized connection (at the PVC bushing - I'm NOT referring to the flex line and never have) and explained to my client that it was pretty picky, but that the galvanized portion should have been done with copper. The homeowner got upset and since had another inspector out (for that and some other things). The inspector called me and we discussed it (although now that I think about it, I think he too is focused on that damn flex line - I know that one is isolated!). So I thought I'd throw it out on this forum to see just how picky I was being... Thanks for the input!

Isn't the cpvc too close to the water heater? I thought it has to be at least 18" away.

CPVC is allowed for hot and cold water use. I don't know of any code section that requires CPVC to be 18" from the water heater. But I will research it. Just because I don't know of one doesn't mean it doesn't exist.

Do you know the section of the code that this may violate?