Finally found the time to remove the water heater outlet one-way valve. It was a brass Marshal valve G784 with 1/2" male threads on each end. The internal check valve made from nylon? or plastic had completely come undone and the little holder opposite the actual valve end had come off and was loose in the water heater fitting after I removed the brass assembly. Luckily was able to fish it out of the water heater fitting. So I'm 99.99% sure I've found the problem and I think I've found the correct replacement on eBay. None of the flaky material from the anode I found in the Water heater was in the valve seat area. The valve just came apart. Thanks for the help.