This thursday, we realized that we have a lot less hot water than before, so I went to check out the tank and sure enough, the bottom element was not heating anymore.
I did a few tests with my multimeter (granted, I really don't master its usage) and it looked like the element itself was faulty. so I went and bought a new element and replaced the old one... no luck
So I figured the thermostat was the issue. Bought a new one, replaced the old one, still no luck.
Now, there is one little piece that I forgot to put back when changing the element and it's basically a small bracket that links both things together which I figured was only there to hold the thermostat in place better.
To put that back in I have to unscrew the element (which means emptying the tank or having a lot of towels nearby). Could this bracket really be what's preventing the element from heating? Otherwise, what could it be?
PS: I know for a fact that the electricity reaches the bottom element as I got shocked a few times while poking around (I know I should be more careful)
EDIT: look at Page 10 Figure 3, TWIST-LOCK flange element part #2 http://www.giantinc.com/tech-data/manual_residential_electric.pdf