Please define "went out" & "kick off". Is the water heater tripping the internal snap disc, requiring re-set, or is it tripping the breaker in the elec. distribution panel? If the former, your thermostat is indicated. I assume you have the 'stats set at some reasonable temp., somewhere around 130F or less. The re-set trips around 150F, but of course depends on which snap disc is used, and my memory isn't quoteable. Upping the element wattage would only decrease the time required to trip the hi temp limit if your 'stats are set too high or not functioning correctly. If the supply wiring is borderline sized, increased wattage MIGHT contribute to breaker trip, as would any direct wiring short. The t'stats need to be in intimate contact with the tank to function correctly, no air gap, dirt, rust etc. Also bear in mind the temp. settings as indicated may not correlate with actual thermometer readings.

This is Jeff, the poster of the original question. I want to thank everyone for their input. The heater is still working- it hasn't tripped again, but now I'm seeing a suspicous dampness on the floor around the unit. It's time for a new one. I have many questions about which sort of water heater to get. Someone here mentioned two 40 gallon units. I'd like to hear more about that. Rather than post my new question here, I'm going to start a new thread, called: Water Heater- which one should I buy? Thanks again. This forum has always been a big help to me.

Kaffine is correct. A circuit breaker will trip if there is excess current draw - meaning an overloaded circuit or a short circuit. It doesn't trip if a high resistance connection heats up unless that causes the surrounding insulation to break down and results in a short circuit. What you saw isn't all that uncommon on heating type appliances or anytime a circuit is cycled at near its max working ampacity. If there is a loose connection, the connection heats up and the wire expands a little. Because the wire is expanding, it also deforms slightly - as does the terminal. When the power shuts off, the connection cools and is now a little bit looser than before because all of the mating parts have deformed slightly. In addition, the heat causes the wire and terminal to oxidize. The oxide isn't a good conductor of electricity and also increases the resistance of the connection. This cycle is repeated every time the heating element turns on and off. As the resistance of the connection increases, it becomes the "heating element" performing basically the same function as the element that's in the tank. To prevent this type of failure, it's important to make sure that electrical connections have good surface area contact and that terminals are tight. On larger connections and aluminum cables, anti-oxidant compounds are used on the wire to prevent the oxidation cycle. In larger installations, preventative maintenance involves scanning a bus, breaker panel, etc. with an infrared thermometer to check for "hot spots" that would indicate a deteriorating connection. This is also why all electrical splices must be in a box. My guess is that there was nothing that would burn near that connection - and that's by design. BTW: There are new breakers out that detect arcing - not just excessive current flow. They are more expensive, but will interrupt this type of problem if it gets bad enough to arc. Any parts that have shown excessive heating should be replaced. In addition, trim the wire if you have some additional length so that the connection is made with wire that isn't damaged with oxidation.

Gray area. Since it didn't do this from the day it was installed, it is unlikely that it is actually wired wrong. Therefore, a component has failed (I'm guessing top heating element as shorted internally). It's two screws, two wires, and a big nut. Either is qualified to find the problem and replace it, but the plumber is more likely to already have a replacement in stock, so I personally would aim this at the plumber. Re-reading your original post, it's 7 months old, there's probably a warranty, so call back whoever installed it (most likely a plumber).