Can someone tell me the source of my rotten egg smell. I replaced the aluminum rods in both water heaters & I Still have that smell. I ocassionally get the smell downstairs (which is served by a different water heater) but upstairs its still real bad. I replaced the anode rods and the problem pretty much went away, but now its back. Had the water tested in 09 these are the results. Calcium 62.2 ppm, iron .25 ppm, magnesium 1.4 ppm, manganese .05 ppm, potassium .8 ppm, silica 34.76 ppm, sodium 2.9 ppm, all else was negliable. I installed a water softner just after this test and then replaced the anodes. Could gasses be traveling to the high point in the system which is upstairs? anyhelp would be appreciated.