Hot water preparation heat pump

Hello, since 07/13 my heat pump has been in operation. Hot water temperature 46 degrees, setback temperature 36. Hysteresis 5k. I am currently testing the hot water preparation. The day before yesterday, around 5 p.m., I heated the 200l tank to 50 degrees. The next morning the temperature was only 41.5 degrees, although only one person had showered by then. 9 degrees less at 10 a.m. is, in my opinion, too much. The circulation pump ran for 3 hours in the evening and 2 hours in the morning. What are your experiences? Yesterday I saw the following in the WEM portal: 2nd HEZ: Bivalence temperature -5 degrees Bivalence temperature hot water 40 degrees. Variable output on timer, probably because of the hot water circulation pump. I have never heard of the bivalence point hot water. What does that mean? Regards

With 200 liters, 50 degrees starting temperature + a nice shower session (after 10 minutes depending on the rain shower head, you might have run through 250 liters) + five hours of circulation and one night, it is completely fine if there are 9 degrees less in the tank the next morning. You will only change this if you use less hot water (turn off the shower in between or reduce shower time or use a different shower head) or reduce the (unnecessary) circulation.

With 200 liters, 50 degrees starting temperature + a nice shower (after 10 minutes depending on the rain shower head you might have pushed through 250 liters) + five hours of circulation and one night, it is completely okay if there are 9 degrees less in the tank the next morning. You will only change that if you use less hot water (turn off the shower in between or reduce shower time or use a different shower head) or turn down the (unnecessary) circulation.

First of all, thanks for the info. So it is enough to run the circulation pump for about 30 minutes in the morning and evening. Do you know what the bivalence temperature hot water with 40 degrees on the heating element means?

Turn off the circulation pump completely! Make hot water once a day, preferably around midday. I have 300l and make hot water to 45°C immediately after the EVU blackout, so that no heating cycle is interrupted. Circulation pump completely off. Enough for 3 people including bathing easily!

turn off the circulation pump completely!

To then turn the dead leg into a breeding ground for germs?
Not a good idea...

then just turn it on once for 5 minutes. But not for 5 hours :rolleyes: