Solar yield too low; how to adjust three flat collectors

Hmm - Do you have ST for heating support? Then the 500 liters are not your drinking water, but the drinking water is heated through the 500 liters. That means in this case the legionella in the storage tank are completely irrelevant - so nothing needs to be tested. (Regardless of who is right between you two *g*)

Regards
Micha

I don’t have ST. Legionella are not an issue for me anyway, since the heat pump automatically runs a legionella program at regular intervals. The drinking water is probably heated to 60 degrees Celsius. I also don’t know exactly how the storage content is divided now. It was just important to me that I can fill my 350-liter bathtub without ending up with "cold" water. Otherwise, the heat comes from the floor and the electricity from the socket—in other words, I haven’t worried much or at all about details.

We also had problems with our system at first, then we had a service technician who maintained the system...

We also had problems with our system at first, then we had a service technician who serviced the system...

And, how many kWh are actually harvested compared to the forecast?

Regards