My heat pump is identical to yours, somewhat of a self install with an heat pump company supplying the unit, cylinder and doing the commissioning. My system is open loop, bungalow, no additional pumps or low loss headers, all brand new underfloor heating at 150mm centres on 100mm PIR between joists. I have no room temperature reference at all at this stage, I’m planning on controlling comfort with the flow meters on my underfloor heating circuits.
Does modulation work similarly to overshoot? I’m finding overshoot very helpful with my pure weather compensation - my heat pump is currently a little overpowered for my house as we are mid deep renovation and only 2/3 of the heating is installed.
I also flatted my curve right off as you have, my heat pump cycles alot below 32C.
Mine went from short cycling to basically running 24/7 at 7L per minute (this will rise as i add more heating loops as it wont need to run so slow to maintain DT5). As you know I’ve got a power meter on the way but going by the MMI it’s boosted my cop tremendously. The power consumption remained very similar (going by ocotpus smart meter data) but heat output increased massively.
On the MMI it simply reads 1KW every two hours pretty much the entire day, with some 2KW spikes when its interrupted by DHW reheat. The mmi listed heat is now 4 most of the time which could mean 4.5kw who knows - will know more once i finish my metering!