Its not corrosion per se, its hard water, or mineral depsits. If it really bothers you sight wise, you can wipe it off easily with CLR, a type of cleaner you can get at any store. Or you can try vinegar. That will clean it up as well. I am not convinced its a leak from what you are saying. It sounds like your water heater is in a basement or wet location possibly? If that is the case, it sounds to me like normal oxidation of brass. White crust often appears on copper or brass fittings if the humidity is pretty high, or other conditions are right. (Where I live, this close to the ocean, my copper roofed cupola got white crust on it pretty quickly...like within a few weeks.)
Of a greater concern however is what that build up is doing inside your tank. I would think you are safe for a few more years but I would pull out the elecrode after 5 years or so and replace it. That mineral deposits will make your electrode less effective and end up costing you more money in electricity to get the same amount of heat into your water. Assuming of course, its an electric hot water heater. If its a propnae or natural gas water heater, you might want to het a burner tech to service it at the 5 year mark, just to keep the crust from causing ineffeciency.
You can get elecrodes at any Home Depot or any hardware store, and they are very easy to replace. A 5 minute job if you know what you are doing, and maybe a 15 minute job if you are a complete novice. Its really an easy mainetance issue/fix.
Last edited by Travis Johnson; 12-11-2007 at 11:51 PM.
I have no intention of traveling from birth to the grave in a manicured and well preserved body; but rather I will skid in sideways, totally beat up, completely worn out, utterly exhausted and jump off my tractor and loudly yell, "Wow, this is what it took to feed a nation!"