Hot Water Heater noise...

[flybouy]

Your water heater may only have one valve also. If that's the case it will be on the cold water line. Mine has one valve and it replaces the cold water "T" fitting of the bypass.

[Skippy38]

UPDATE: I drained the water heater and reestablished the air gap and it worked great for a couple of days. Now the water is back from the pressure relief valve so this is obviously the root of my problem. I am going to replace with a similar unit from Home Depot and will let you know the results. The sound is still there although not as bad, but that is another item. Thanks for all of the consulting.