Correct temperature for a 300-liter hot water tank?

70° alone is not done by a heat pump. The heating rod has to come into play then.

Yes, that is the problem, that legionella simply do not want to adapt to heat pumps and agree to die off already at 50 degrees water temperature

Or size it so that Legionella have no chance at all. After all, a single-family house is not a swimming pool.

And we also won’t go on vacation anymore because otherwise the water will go bad. Why not just heat the water once a week with the heating rod?

The question is whether it is really necessary. Otherwise, the German rules are always so strict, and of all things, here they are so lenient?

With 200 liters in the system, heating from 50 to 70°C costs you about 5 kWh. That makes 60 euros per year. Many people switch their car insurance for that.

I just wonder if that is really necessary. We actually manage to empty our storage regularly. And no one prevents you from doing it once after the vacation.

I drive it at even 45 degrees! And the circulation does the rest.

If you have a lot of concern in this regard, you can also install a 300l tank with a fresh water station. Unfortunately, it costs a bit more. I had a fresh water station in the old house and have to say that it is great. With proper dimensioning of the tank, however, it is also unnecessary.