Hi Glyn, did you that if you set 20 it reached this temp, it’s off until it drops to 19 and then turn on right ? Still I don’t understand why there is no hysteresis possible to set on this controller. E.g. 0.5C. 1C is pretty big drop you may fell.
Could you please reattach the video ? It was removed.
I will get PWM cable today so let’s see if it run better in higher temperatures. I still don’t understand why this pump has so short cycles… Really. I would be ok with 15 minutes or 20 minutes but 7/3 is very short and it’s only 5C here. What it will do when there is 10C or 15C ?
Your pump would be much much better for me and I regret I didn’t investigate more. I could find this forum sooner but it’s very hard at the beginning if you have no idea and you only find out when you buy it. As I can see from graph it can go as low as 500W power input which would solve my problem and that thing would not cycle until +10C! Unfortunately this shit I’ve bought can’t go lower than 1KW 
@Ian_Calderbank @matt-drummer @SarahH
Not sure if there is not some other problem. I just watch how it works
Flow temperature was 40C
Return 32C
So this is dT = 8. It even didn’t reach dT = 5. It didn’t approach dt=5 and it turns off the pump, why ??? Could it be because flow was too low and dT was increasing instead of decreasing ? Flow was 9.2 lpm. I can imagine that if I have PWM the HP would require flow over 20 lpm so not sure but maybe this is also problem? I really hope that by installing PWM regulation to my pump it can work more efficiently. Really hope.
Set indoor temp is not satisfied but for some reason the pump switched off! How ? Why ?
Also what do you think - can those short cycles have an impact on a HP life? How bad is for this scroll compressor to turn off and on every 7 minutes, or 3 minutes respectively.
My problem is now that I set desired temperature to 23C but the pump never got there because of short cycling. It reach max. 22.5C for this reason. What can I do guys. Increase LTW ? But then the curve could be pretty steep. I like 40C at 0C - if it’s running constantly it can satisfy my heat losses and temperature. But when there is 5C outside 40C can’t be delivered by my K2 radiators and current flow.
Well, I’m doomed 
Here is the graph from last night. It wen fro1C to 5C in the morning and cycling nightmare started:
