Hi @svas, I also agree with the diminishing returns, its funny how we chase the most efficient machines, I try to not be wasteful, but another perspective, our IT equipment sucks ~250w 24/7 and I do not think twice about that, equally I would not think twice about driving my electric car to watch the rugby that would use a load of electrons…. I have gone back to LWT but flattened the curve to try to hit a LWT of 33 DT5 at 5 degrees and the house temps are now stable….we are in a privilege position of affording the electric bill and even if the HP is on 24/7 and uses 12kWh per day over the winter period (4 months) at 26p per unit (ignoring the solar, battery and 7p off-peak rate) we would spend £374, as noted on the ESPAltherma thread I have implemented a Generic Thermostat control to cover the warmer days if the house does overheat and just turns off the HP.
40 @ -15
31 @ 11