That page of their manual is my bible. It’s what I’m using to draw the “nominal” parts of the efficiency graph.
There’s no time like the present…
As you can see, it’s trundling along happily. It’s using 1.6kW though which is more than we’d typically be using. Here’s a recent comparison from a slightly colder day where the average is just under 1kW.
I’ve never seen it running stably like this for a long period of time, so now I’m seeing a thing happen that you all talk about that we should expect. The outdoor temperature went from 7 to 8 Celsius at 10:48. About 3 minutes later the return temperature also went up. That might be because the house is warming after an hour running the pump or it might be correlated with the external change. However the same thing just happened when outdoors went from 8 to 9…
So I think the changing external temperature is going to knock it out of steady-state because it’s getting above the target flow. I’m going to keep watching to see.
Of course if I raise the target flow to match the increased outside temp then the radiators will get even hotter and the house will get hotter and at some point it’s just going to be too much. Of course my efficiency will also fall - although it’s current 381% is pretty impressive. At the moment it’s modulated down to it’s minimum of 26Wh per minute (1.56kW) so we’re stuck with that well known problem of a device that’s rated for cold weather struggling to modulate down when it’s warmer. It’s a bit sad that the target cold temp is -2 and the current temp is 8 and it is struggling to manage comfortably across even that small range.
Here’s the buckets of power usage since 2019-10-01:
So it can go down to 1.08kW but it doesn’t seem to want to.
Clearly “off” is it’s most common state by a long way.