Thanks for the reply Larry.
As I said in the first post, both elements tested fine.
Not too worried about the gate valve, just adds insult to injury on top of all the other issues, and I thought it worth noting in case it might have anything to do with the WH not working, or the leaky drain spigot.
I can’t test the lower thermostat to see if it turns off when hot because I can’t get the WH to turn on either of the elements at all anymore. Last time I was able to get it working I noticed the upper element cycled on first, shut-off, and then the lower element cycled on. Doesn’t the upper thermostat have to cycle on first before the lower one?
I’ve read a few posts where it was suggested that air in the tank could cause the thermostat to fail if it was drained and then filled without “purging” the air before turning it on again. Is this true, and if so could my landlord have fried the upper thermostat if he improperly drained the WH to clean the sediment from it?
Based on all the evidence, it would seem the upper T-stat is bad again.