The high limit switch has popped twice on my electric water heater, both times at night. I reset the switch and the water heats and it's ok throughout the day. Wake up in the morning and it's popped. I tested the switch, thermostats, and heating elements with a multimeter and everything seems ok. I'm getting 243v through everything and continuity through both upper and lower elements from what I can tell.
Any other ideas or should I just replace parts until it stops?
The limit switch wasn't adjustable and the water was getting quite hot regardless of the temp setting. The temps were set where they were supposed to be, but then it kept popping even after I set the temps to the minimum level "hot" setting (this was below the A,B,C area even). I ended up just replacing the top and bottom thermostats and so far so good....total cost of 24 bucks and about ten minutes work. Calling a plumber would have cost me about $125 for anything within the first hour of work.