I’ve noticed a possibly odd situation since the ASHP has started to do heating again, before it actually kicks in my flow rate starts oscillating like below, taken from 11th Sep 2026:
I thought this never used to happen, but I’ve actually looked back at data and it did use to a bit actually, the below is taken from May 21st this year:
And the fan speed did do the same (the below is from Grafana as home assistant has put the stats in to long term and I can’t use them now, they are not granular enough):
I’m not sure, maybe there’s air in the pump and it’s self priming? Make sure the system pressure is topped up, automatic air vents are open and maybe and try bleeding the highest radiator.
Playing about with this last night, I was a bit tired so can’t fully recall exactly what I actually changed but I went in to econext → H1 and chose “heat” and “comfort” and it’s not happened again yet, lets see…
@glyn.hudson on an unrelated note, I see on your emoncms graph your target temperature moves in nice smooth .1 increments, mine only moves in integers, if I look at sensor.heat_pump_target_temperature I can see this only ever moves in whole numbers - I notice yours used to do this, I presumed it was a limitation of the heat pump to be honest but perhaps not! What did you change?
Ahh yes I was just reading, you used sensor.h1_calculated_temperature I think - I’m using sensor.heat_pump_target_temperature, does that sound right?
Also out of interest, do you still have the DHW sensor connected or do you just use sensor.ecomax360i_flap_valve_state to drive CH/DHW detection?
Edit - well I used the HA entities above, I don’t think you use HA at all to push to emoncms, but you’re using the same values regardless I guess, e.g:
ok so no this hasn’t changed anything, wondering if i perhaps have some odd settings applied, mind scanning through these @glyn.hudson if you get a spare moment any time and seeing if yours are vastly different in any way you find relevant?
Interesting, my ASHP firmware isn’t new enough to take advantage of the pump speed AFAIK so those differences probably won’t matter. Grant are sending an SD card which they say will update the controller firmware and I think also the ASHP itself, will see if that happens!
Not sure if the Circuit temp. from pump return matters as well, from what i can see that only matter if you have additional circuits, unsure there!
Interesting it is happening to others as well, is yours on auto winter / summer? I did wonder if perhaps my “summer mode off” of 17c is a bit high?
Useful to see your settings as I’m playing around with mine as the heating system gets under way. One difference is that my “decreasing fixed water temp” is set to 2ºC. Curious as to what that does…
