Hello, I have a 7 year old EnviroTemp (American) gas water heater with R110RTSP gas control valve. It has a small gas leak from under the valve dial (I can smell gas coming from there if I move my nose close to the dial). It seems to be a common problem with this valve as I researched on the internet - http://www.nachi.org/forum/f22/unitrol-gas-valve-leaks-water-heater-28573/. I know there was a recall on these valves but my valve is not under that recall. The heater itself works fine otherwise. I investigated the anode rod in order to figure out wether I should replase the valve or the heater itself but the anode rod is still intact although it needs replacement. So I think it is more economical to replace the valve and the rod rather than the whole heater. Removing that anode rod was an adventure by itself because it requires just unbelievable gut-busting force on a wrench in order to unscrew it! I could not do it by force so I had to come up with a device which I would like to share with you all. In order to unscrew the anode rod I needed 1-1/16 socket wrench, 24" pipe wrench and a car jack. I placed the pipe wrench between the heater nipples (removing draft hood first) and wedged a car jack between the pipe wrench and socket wrench handle (you can see the set-up on an attached picture). Then expanding the car jack I was able to exert a great force on a socket wrench and unscrew the anode rod. It worked great in a confined space and I think one (not very strong) person can do it without external help. Now back to replacing the valve. I looked on the internet and gas control valves are pretty expensive. You can pick up one at lowes for $60 (R110RATSPL) but it has different main burner pressure of 5". Valve currently installed on my heater has 3.5" main burner pressure. My questions are: 1) How important that main burner pressure for correct operation of water heater? 2) If it is important is it possible to adjust the pressure on a newer valve from 5.0" to 3.5" (I know there is a pressure tap near the main burner tube for the manometer)? 3) Any suggestions on where to get a valve with a short shank and 3.5" main burner pressure on the cheap?