ᐅ Water temperature in 300-liter tank – air-to-water heat pump with underfloor heating, photovoltaic system, and controlled mechanical ventilation with heat recovery

Hello everyone, what should the optimal water temperature in the tank be?
We have been living in the house for 6 weeks. I always see the temperature between 52 and 40 degrees Celsius (126 and 104 degrees Fahrenheit).
I also believe the installer said he sets a maximum of 52 degrees Celsius (126 degrees Fahrenheit).
Is that sufficient to prevent bacterial growth, etc.?

P.S.: Another question on the side: How and where can I check the flow temperature of the underfloor heating?

In the ros a forum, a temperature of 50°C (122°F) with a 6°C (11°F) hysteresis is always recommended. Please note that if a circulation pump is installed, your tank cools down quickly and the heat pump cycles frequently. I had issues with this because I set blackout periods at night. In the morning, the water was sometimes at 35°C (95°F).

What kind of air-to-water heat pump do you have installed?

What kind of boiler is installed? Is it with instant water heating or a storage tank?

Okay, then it seems that this actually fits. I always assumed 60 degrees Celsius (140°F) once a week or something similar to prevent the issue.

We don’t have circulation. I’ve already missed that. But based on your comment, I can cross that off.

The boiler should be this one: Elco VISTRON H-4. I don’t remember exactly from memory, but the picture matches.

Our heat pump is the ELCO Aerotop Split 07M-R. Besides the 300L (79 gallons) storage tank, we also have a 100L (26 gallons) buffer tank and a 30-liter (8 gallons) expansion vessel. It all seems quite large to me.

Double storage? I think that’s nonsense; I’ve even read that it might be better to disable it. But there are experts who have studied this and can provide more detailed information.

Circulation is a matter of comfort but comes at a cost. We were above 5000 kWh for 250 m² (2700 ft²), and after optimization by disabling the heat recovery ventilation (HRV) and performing thermal balancing, it looks like we’ll end up around 3500 kWh this year. Okay, the winter was mild.

But money saved, and I’m Swabian.

tomtom79 schrieb:

In the ros a forum, 50 degrees with a 6-degree hysteresis is always recommended. Please note, if a circulation pump is installed, your tank cools down quickly and the heat pump cycles frequently. I had problems with this because I set night-time restriction periods. In the morning, the water temperature was sometimes as low as 35°C (95°F).

The circulation pump should also not run 24 hours a day.

The circulation had a learning function, but it probably conflicted with my shift work.