I made a video of what I look for when inspecting an electric water heater. The first thing I like to do is note the brand, age, and capacity. I then look over the tank for signs of rust, corrosion, or leaking. Next I will check for the presence of a TPR (Temperature Pressure Relief) Valve and make sure it’s placement on the tank is appropriate and the it’s extension is adequate.
I then look at the inlet (cold water) and outlet (hot water) pipes and make sure they aren’t reversed. While I’m checking the cold water inlet pipe I’ll note the presence of a shut off, there should be a water shut off and it should be on the cold water inlet pipe.
Finally I check for a drain valve at the bottom of the tank, water heaters should have one. Here is a short video of my process in inspecting an electric water heater: