I was winterizing our 10-year-old coach and flushing out the water heater. Some scale, I know, is usual, but what came out were lots of blue flakes. I am assuming that this is the glass lining of the tank and that the heater is basically totaled and not usable. I’d be very pleased if you could confirm that for me. —George N.
Unfortunately it is relatively easy to inadvertently scrape the inside of the tank if you insert a long wand or tube inside the drain plug as you flush out the inner tank.
One way to determine if the flakes are actually pieces of glass or the chemical result of something else, is to put a few of them in a cup of vinegar and see if they dissolve. If they do, then it’s probably some type of mineral deposit that reacted with the composition of the water in the tank. If they do not, they could be little pieces of the glass lining, though I’m not 100% certain they would be blue in color.
Assuming they are indeed glass slivers from the tank lining, the obvious safe action would be to replace the complete water heater (or at least the inner tank), and not take any chances of having them migrate further into the hot side of the fresh water system.
It could simply be some type of mineral reaction between the anode and the water PH and the heat associated with the heater. But finding out what those flakes really are is the key!
By the way, the photo above is what your Suburban inner tank might look like before it is glass-lined.