The heating element broke a while ago (like a few years ago #procrastination) so finally today I have repaired it with the spare part that got sent to me from China. Yes, also a few years ago already.
Water now stays nice and warm and the first thing that needs another cleaning are the Honda CBR600F Hurricane carburetors. I was probably too quick with assuming that the carburetors were clean, eventhough I manually opened up all the jets and made things flow again. The engine even started right away but a motorbike garage said no. So, everything is now taken apart and by doing so, I also noticed that one jet was missing a REALLY TINY rubber o-ring.
I dont's have stuff like that in stock, but then I remembered that I had a few used Keyster carburetor revision sets for a CB400N laying around and whaddayaknow, there was a REALLY TINY o-ring in there. Ha! More news about this CBR soon.