Which stage is suitable for the storage loading pump (Wilo Star)?

Hello again,

with my Wilo Star storage charging pump (285L storage) I can choose between 3 power levels (41, 54 and 63 watts).

The heating engineer had set it to level 2, but the customer service of the heating control (district heating) said that could be counterproductive due to too high return temperatures and worse utilization of the water temperature.

I have set the pump to level one. The flow noises decrease significantly.
The storage return temperature has not noticeably decreased, so level 1 should be sufficient in my understanding. Or am I thinking wrong?

Hello,

....with my Wilo Star storage loading pump (285L storage) I can choose between 3 power levels (41, 54 and 63 watts)....

First of all, it needs to be clarified, storage for what? Hot water or heating or combination. Also not unimportant is the type of storage, parallel or separate storage?
Not all feedback effects can be described by short-term instantaneous considerations.

Kind regards

It is a hot water storage tank for domestic water. Type Wikora 305 Duo with two smooth tube heat exchangers (no solar connection yet -> water remains cold at the bottom).

It is a hot water storage tank for domestic water. ...

So a typical separation storage tank for hot water with a solar thermal system option. I would not assume that a solar thermal system is worthwhile here.
The lowest pump setting is sensible here, possibly already too much! Even this seems oversized. Whether a pump replacement is economically sensible, however, is uncertain without knowledge of the boundary conditions.

best regards

The lowest pump setting makes sense here, possibly already too much!

How can the required pump capacity be determined?