[Sproket]

Well I have always used Distilled water. I was saying that it was probably tested, not by me, with tap water and some left in there or something.

Well I actually used 100% Drano last night and Wow, it is actually a brass core, look like white metal before. Brown foam was coming out of the Rad and coming out. Real dirty in there. Im going to run a 50% mixture of Drano tonight through it to get the rest. I just put Drano inside Rad and let it sit, then attach a hose to one barb and to the faucet and let water run through. Then hook up spare pump to rad and place in bathtub and clean well w/ water. When all done run 5 stage RO water through it. Then it ready for distilled.

I also leak tested after using Drano and No leaks in the heatercore.


My copper block had no signs of this inside. It was all clean.
Im not using drano on block!