[Lynn]

Tony:

I know there are lots of flush products. Most have chemicals to eat stuff (for lack of a better term). I have always avoided them as you never know when it might eat something you want to keep. I don't think you can do better than copious amounts of water.

To get everything, you will have to remove some hoses. Take out the Tstat. Run lots of water using a garden hose. Flush from both directions. I always flush the heater core separately. It is messy, but don't think there is a better way.