@papahuhu Here is a more detailed plot of the OAT on its’ own for today; not much change there. Regards, Toodles.

@papahuhu Can’t say that I have noticed any changes whilst standing near our monobloc; I think I have heard it running at perhaps 2, maybe 3 different speeds at different times (days or even weeks apart) but then, I don’t stand out by it that often! Our ambient noise level is dictated mainly by main roads on 3 sides of us, railway services to the north and also to the south west of us, police and emergency services sirens all round us and aircraft overhead!!! I have to stand within about a metre of the heat pump front to hear it running. Regards, Toodles.

@toodles Quite properly, I evict myself from the house if I want to smoke. So, I get to stand near the outdoor unit more frequently than is good for me. It’s rare that I don’t hear a change a tone whilst out, just small deviations up or down. So something is causing the micro adjustments, I assume it’s the homely driving this but I can’t be sure.

I remember you saying you were on cosy, did you take the fixed deal or the variable, I ask because I notice the new rates are higher and fixed fir 6 mths. I tried to change to IOF but was temporarily blocked whilst they see what’s happening with prices. Chaos is coming, thanks to our highly objectionable friends. 

@papahuhu We are still on Cosy; I didn’t ‘fix’ as I expected to move to IOF within the 12 months penalty period, thus losing £25 which would be more than the difference for our consumption between unfixed and fixed rates. (Who Knew!!!????). Why can’t peoples learn to live and let live eh? Regards, Toodles.

@toodles 

Hopefully you won’t be importing much energy over the next 6 months.

Yes, the world is a mess and getting worse at an accelerated speed. With the nightmare that Huxley, Orwell, Nietzsche and Baudrillard were seemingly prophetic. When you have the CEO of Anthropic refusing lucrative state contracts on the basis that the technology is unsafe then you know that very big trouble is just round the corner.

@toodles 

out of interest I took a screenshot, first thing before the variable house loads started,  of the PW home demand. You can clearly see the small variations in power demand that I can hear. Does your heat pump not do the same thing please?

@papahuhu I don’t think I could make any such comparison as I have so many factors in the background domestic load, even if I could see the variations. We have a NAS, a network system with two wifi repeaters, a ‘fridge, a ‘fridge/freezer plus numerous ‘always on’ items around the house. Everyone of the non-constant drain devices will cause variations in the readings of course. Hand on heart, I don’t think I could detect any heat pump load variations if I tried! Regards, Toodles.

@toodles We also have a base load of about 300W too. But fundamentally they are different profiles, mine is slightly oscillating up and down, but not cycling. I don’t know if it’s good or bad nor what is causing the signal for that to happen. It does the same thing in very cold weather, so it isn’t because it has reached its minimum output.

@papahuhu Perhaps it is down to the hysteresis of a control loop within the heat pump? I have not noticed such oscillations in my system - though that doesn’t mean they aren’t there for all that!

BTW., Our base load averages ~300-400 watts but, I have noted times where this might drop to ~100 watts and stay there for 20 minutes perhaps then rise to ~450 watts for a while. That might be caused by different units consuming in synchronicity -  and then at irregular intervals out of sync. with others?  Regards, Toodles.

@toodles in my case a little knowledge is useless, but I understand that when the pumps operate at low speed (or constant speed) there is a propensity for the lubricatiion oil to get “stuck” in the evaporator. One of the strategies to redistribute the oil is to pulse the speed up to shift it back to the pump, a bit like a sneeze or a cough.

Or, most likely, this has nothing to do with it. 

@papahuhu Sounds plausible - I suppose, depending on the viscosity of the fluid, this ‘cough’ may be required at intervals. I have not delved into such matters at all but perhaps a reader with greater knowledge of heat pump compressor inner workings might care to ‘chip in’ to enlighten us please? Regards, Toodles.

Posted by: @benson

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@johnnyb interesting. That is quite a difference.

I've been comparing our consumption, and COP, from last years readings from the wired controls when I had homely. I think I've finally got the native setup and control side of things spot on after a bit of tweaking over the winter months, and this is the most recent monthly data (Clivet ashp):

With homely: February 2025 (average OAT 7°C): 1089kWh. COP 3.31

Without homely: February 2026 (average OAT 8°C): 733kWh. COP 3.94

I now have my wired controls connected to home assistant via modbus. A simple automation sets the outlet flow temp according to OAT, with another automation making small adjustments if under or overshooting our comfort range. Our house is also kept a degree or so warmer this year, and the IAT is more stable. Oh...and all of the monitoring functionality that I need.

 

I was reading your thread about your change from Homely to HA at the weekend and I would like to do something similar once I have time, but that is a way off at the moment so Homely is an easy option. 

Reading the post by @odd_lion that I hadn't read when I posted, it doesn't seems like mine is the only one that is a lot different to the HP controller figures.  Was your Homely installed by your installer @odd_lion?  The guys who installed mine are fitting Homely as standard now but weren't when I had mine installed.