I replaced a w/h, and the new install was an American that had the gas control similar to the B-W Icon. So, I kind of liked it and found that the valves can possibly be fitted to the pre flame-guard systems. Got a 50 gal. State in my home, and would like to try out the retro-fit. Anybody tried the retro-fit? Just an experiment for me, and no, I don't want to change to a flame guard in my house. I'll buy a standard 100 gal. first.