How do temperature fluctuations occur in fresh water?

Again: what does "before" mean. A good fresh water only needs a delta of 1-2 degrees between buffer flow and hot water outlet. But 60° at the fresh water is already intense, once because of the energy demand and then also because of lime. What hardness does your water have?

Again: what does vorher mean. A good fresh water system only needs a delta of 1-2 degrees between buffer flow and hot water output. But 60° at the fresh water is quite intense, partly because of the energy demand and also because of lime scale. What is the hardness of your water?

Hello.
60 degrees at the fresh water was specified to us, as this is a multi-family house with 5 units. It is supposedly a regulation for multi-family houses...
I myself would go for 55 degrees.
Water hardness is not that hard. About 10 dH. So lime precipitation is not that severe.
The buffer currently has about 65 degrees. Between buffer and fresh water there is a limiter installed at 65 degrees. Thermometer flow to fresh water mostly shows 60 degrees. Fresh water display flow, however, shows 65 degrees.
Fresh water currently at 58 degrees, circulation currently at 53 degrees.
So with this data the fresh water should run without fluctuations.
But the warm water always has to be readjusted because the temperature is not maintained.
That is why it amazes me that these fluctuations occur.

Again: what does "before" mean. Good fresh water needs only a delta of 1-2 degrees between buffer flow and hot water outlet. But 60° at the fresh water is already intense, once because of the energy requirement and then also because of lime scale. What is the hardness of your water?

Addendum: The buffer volume for the fresh water was generously kept at 1000L. The sensor was moved slightly downwards. Therefore, a lot of the approximately 60-degree heating water is available for the fresh water.

Then take an inexpensive IR thermometer and observe the actual temperature curve at the hot water outlet of the fresh water during a longer tapping process. It should be approximately the set temperature and nearly constant. Possibly, the loading pump reacts too slowly or too inaccurately to changes in flow.

Then take an inexpensive IR thermometer and observe the actual temperature progression at the domestic hot water outlet during an extended draw-off process. It should be approximately the set temperature and almost constant. Possibly the loading pump reacts too slowly or too inaccurately to changes in flow.

All right. Can you send me a message with your email? Then I could send you photos. Thank you

All right. Can you send me a message with your email? Then I could send you photos. Thanks

No, because that is not the purpose of the forum. You can gladly post it here.