As I was making the first mug of Joe for the day, I noticed the water was taking a looong time to come to a boil in the microwave. I always use water from the hot spigot when I rinse out the glass carafe for my fancy, high falootin' French Press coffee pot. Then I put my measuring cup under the spigot and fill it, and put the water in the microwave.
Right about this time my wife comes downstairs and announces "We Have No Hot Water". This puts me in Fix-It-NOW mode, as an ample supply of running, HOT water is something SWMBO insists on, and after taking a cold shower before starting on this project, I agree rather strongly that hot water is quite nice.
The water heater is down in the basement (aka "The Dungeon"), and it's all the way in the back of a storage closet that was built when they finished off the basement, and made it usable living space. SO.....the first thing I had to do was lift out the storage shelves, which are made of some density of particle board that's heavy. The manual for the water heater was on the top shelf, so after I pulled the shelves, and the "earthquake barrel" full of emergency supplies, I sat down to read the manual.
Right there, in the troubleshooting guide, under "NO Hot Water", the number 1 cause was the "High Temperature Limit Switch Open. Push To Reset and Reconnect Power".
Naaaaa....it couldn't that simple, could it? I turned the breaker off, and then pulled the cover for the top thermostat and element off. I pushed the red "RESET" button, and it clicked. Turned the breaker back on, and after about 15 minutes we had hot water again.
I can replace both elements, and the thermostats, for under $75, which is a whole lot better than the cost of an entire new water heater. I'll watch this, and if it trips again, I'll just replace all of it.