Get this: 4 plumbers have been in here, if you include the guy from Enbridge. The first one replaced an element, which had no impact on the water temperature. The 2nd one didn't have any suggestions regarding the water temperature. The 3rd one suggested that I buy a new water heater, so he didn't really understand the problem. I thank the Enbridge guy for finally explaining why I can't get hot water, but he refused to touch the mixing valve and he refused to consider removing it. He said it's not his problem because it's not part of the rental. I'm pretty sure they were both installed at the same time by the same person, but whatever.
So with that kind of help, I really may have to do it myself. Good thing this website is here...
I unscrewed the knob to see why it wouldn't turn when I tried to adjust the temperature. I still can't twist what's underneath it, but then, I don't have the correct size socket wrench.
Here's some more pictures. Any suggestions on how to adjust the temperature? I just want to see if I can adjust it first before making plans to completely remove the thing.