At 6:00 pm on Sunday the hot water decided to stop flowing completely. About a half hour of Google led me to checking the cold water inlet for blockage as apposed to the hot water outlet which was my natural thought. I turned off the cold water and disconnected the line from the water heater then turned the water back on. OK water is flowing all over the place, what should I do next me thinks. Ok I drained 5 gals of water out the bottom of the tank, reconnected the cold water line, turned on the water. Hmmm I don't hear any water flow and it should be filling in the 5 gals I drained. Next lets disconnect the nipple and see if it's clogged. eureka it's clogged! Quick trip to Lowes at 7:00 pm on Sunday and $9 later I can take a hot shower tomorrow. I wonder what a plumber costs on Sunday at 7:00 PM?