Good morning, David.
- The main downside to enabling weather compensation is that it will always result in faster compressor cycling than roomstat control, simply because the thermal inertia of the circulating fluid (even including the radiators and piping and any volumiser/buffer tank) is far less than that of the house fabric. It only takes a few minutes to re-warm the circulating fluid by its hysteresis value when you are bashing several kW into it (even at minimum compressor speed). Whereas it might take the best part of an hour for the roomstat room to re-heat over its hysteresis value.
- Your results do seem to indicate that you have #2091 set to 4, as you say. I wonder whether you have misinterpreted the setting - see my point 2 in post #28 above.
- I’ve never really understood why Samsung are fixated on circulation pump operation, in particular why they offer the 3min on/7min off option. To my simple mind, with a cycle time as short as 30-60min, you only need the pump to run whenever the compressor is running (albeit with a minute or two run-on to dissipate any Outdoor Unit heat build-up). I can only assume that this option is aimed at smoothing room temperature changes (though it’s costing extra pump energy of course).
- I think most folk would be happy with a 45min cycle time when weather compensated - that’s what I would expect with a largish heat pump (say 8kW nameplate or more) with a 2K hysteresis on a 100litre circuit. I think Samsung recommend a maximum of 3-4 cycles per hour, so you’re OK there.
- Nor would I worry about room temperature variation (provided the roomstat is located in a sensible place like your living room). With no heating at all on a cold winter’s night, my living room cools at about 1K/h. My heat pump also has a 40 minute cycle time, and I don’t notice the 0.5K room temp reduction when it’s in its “off” period.
- In summary, it sounds like your system is working fine
, but keep us informed of your operation once winter starts…
Sarah