I just moved into a new a new apartment a month ago (newly renovated) and the electric water heater (I think it's him, not 100% sure) is making a squeaking noise. I talked to the electrician and he claims it is normal. The noise isn't constant, it is happening 2-3 times a day for about 20 minutes. In those 20 minutes you hear the squeaking every about ten seconds. You can see it in the video. The sound strangely also exists when the heater is turned off (powered off the electricity). Anyone knows how to fix it?
Here's the video of the behaviour. https://youtu.be/pEPRzM9ME0Y