Hello: There is a simple fix for the recirc line problem. If you have a ball valve on the return near the tank, close it nearly all of the way. The problem is that when you draw hot water, some of it is flowing backwards through the recirc line carrying sediment with it. In normal operation the recirc moves water quite slowly. a valve only partly open allows the slow flow but does not allow enough flow to carry sediment back up the line. It will take some time to get the right adjustment. When you find it, remove the handle and tape it to the pipe. Otherwise garden gnomes will mess with the handle 😎
Thanks for suggestion but I tried that a long time ago. Over the space of a couple of weeks I closed it a little at a time until the line started to cool then backed off a hair.
I’m going to install a powered anode and I am sure that will do the trick.