White "powder" on heat exchanger - corrosion?

[shanti_83]

I have had this problem since last summer after I changed the zinc anode on my heat exchanger and took the heat exchanger apart to clean it. It seems as it has started to corrode on the outside. The paint is falling off, and I get this white "powder" that almost looks like salt, but it's not. I am using a lubrication product called Fluid film and spraying it on the heat exchanger from time to time. This helps a bit, but recently it has been very humid here, and the problem has got worse. I really want to fix it, but don't want to take the heat exchanger out one more time since this is a lot of work. There is not any leak anywhere as far as I can see, but something is obviously wrong! Grateful for any help!

 

[vyv_cox]

Looks like a leak to me. I assume that is an end cap with a seal/gasket of some sort. Can you take it off and apply some gasket goo?

 

[Yngmar]

Definitely a leak. It doesn't have to be dripping, a small leak can do this.

 

[shanti_83]

Ok, thanks for the answers! Seems like everyone agrees it is a leak. The strange thing is that its not possible to open this end of the heat exchanger, but if the zinc anode is leaking I guess the humidity can spread over the whole area. I will try to seal the zinc anode screw better I guess..