Hi Matthew,
Welcome to Emoncms!
I found that my heat pump was cycling too often as well. Yours doesn’t seem excessive at three per hour. Our house is also 1800 stone with little insulation. We don’t have a buffer, but we do have large rads with TRVs.
In this post you can see I got benefits from running the heat pump for longer runs. Notably with mine it took a few minutes to start working efficiently so I wanted runs of 10 or more minutes to amortize the start up costs.
Note that our desired flow temp for the space heating has also been around 40 °C because it’s been kicking in when the effective outside temperature was around 0 °C. Our weather compensation is:
compCurveValue = int(38 - 2 * effectiveOutdoorTemperature / 3)
So for your Te’s the Tm’s would be 35 and 25. If you’ve only had it installed recently it might be worth just letting it run as the installer set it for now and seeing how it goes. Notably those temps are for our rads because we don’t have a buffer. Is your system applying that curve to the flow temps or the buffer tank water temp?
I’d also expect yours to do less cycling than ours because you have a buffer tank. Perhaps your buffer isn’t really getting terribly cold so the heat pump only has a tiny amount of work to do to bring it back up to temp. In that case your intuition that it can run longer but less often would seem well-founded.
I’m a little surprised it’s got enough demand to cause cycling though. In the last few days our has only come on a few times.
