What flow temperatures are you currently running?

Controllers and control loops are really a topic of their own. I completely agree with , too much theory just confuses. When setting a controller, I believe: trying beats studying, or rather try first and then study the effects ;)

I still find it helpful to have in mind what the P component and what the I component do in a controller.

A picture is worth a thousand words here. Unfortunately, I can’t upload attachments from my phone :rolleyes:

Just try googling "step response PI controller".

A different question: I have lowered my heating curve a bit again, from 0.16 to 0.1. Now the heat pump cycles 15 times in 24 hours at an ambient temperature average of 7°C in 24h. With a heating curve of 0.16 and the same ambient temperature, it cycled only 3-4 times. What is better now? Lower heating curve and more cycling or a slightly higher heating curve and less cycling?

That cannot be compared. Lowering the heating curve makes it colder. To achieve this, the heat pump must be off more frequently or for longer. It will consume less energy, but the heat pump may not last as long.

. What is better now? Lower heating curve and more cycling or slightly higher heating curve and less cycling?

How high is the hysteresis on your heat pump?

How high is the hysteresis on your heat pump?

I can't adjust that on my heat pump There is only heating curve steepness and heating curve shift. Steepness is set to 0.1 and shift to 0

I suspect you won't manage with 0.1 in winter unless you have a super-insulated house.