I've run into a electric power problem today that I can't seem to explain it.
The problem began when I opened up the warm tap water and I heared a sudden loud noise coming from the instantaneous water heater; I realised afterwards that power went out.
I noticed then that the kitchen (fridge + electric plates) still have power but everything else can't have it anymore even when I reset the breaker.
Surprisingly, I noticed that when I turn on the warm tap water, power comes back again as long as the warm water is running (when I close the warm tap, power goes out).
Is there a reason that could explain how power only functions normally when I switch on warm water?
Best Answer
Your heater is a three-phase load, most likely with the heating elements connected between the phases.
I'm not an expert on german wiring practices, but my guess would be that your heater has developed a short circuit in one of the elements, said fault blew out the fuse supplying one of the phases and is now back-feeding said phase. Whether said fuse is your responsibility or your electricity suppliers responsibility I could not say.
I would advise against operating the heater until it has been inspected by a competent service technician and the supply fault has been rectified.