This is a copy of a question I sent to Ask This Old House hoping for a reply soon???

Hi: This ? is for that resident expert Richard Trethewey.
I have that sulfur smell in the laundry room sink when the hot water is used. Here's the kicker: thatís the only sink that has this problem. I've tested other sinks, some closer the hot water heater(electric)but I don't seem to have that smell anywhere else. I know that thereís only one WH for the house(4yrs old) as I personally helped in it's construction. I have purchased a new anode rod but I'm hesitant to install it if there could be another explanation. Iím at a loss to explain this. Can you help???
P.S. I love your show and watch as often as possible...