Best way to clean calcium build up out of a radiator??

604 said
About two days. I was a weeny and worried about it with the warning on the bottle. I know I am a chicken. LOL

I may have to try the vinegar, just i read on line that it can dissolve lead. May not be true. Who knows

Naw, you just didn't know. You can leave it in a while when it's diluted that much. It won't hurt anything.