I have removed the core from the heat exchanger on my BZ482 and noticed a buildup of white corrosion on the solder joints. It also seems that the solder has deteriorated somewhat. I have done a bit of research on this and this condition is called "solder bloom" . Has anyone else noticed this? I am going to flush the system and use a different coolant. In the attached picture, unfortunately most of the corrosion has been scraped off. Colin...
Your tube stack appears quite serviceable and should not give any problems. The issue that you have is really a consequence of the type of antifreeze that you have been using or the antifreeze has been in too long.
Re-install with some new "O" rings, fresh antifreeze, and you should be be fine.