@papahuhu I have apps on update and check (sad that I am) daily. ISTR that Tesla app updated in the last few days. Toodles.

@toodles It was the colour that threw me, yours was yellow whilst mine was blue, green and grey. Now I know why!

Very occasionally IOF does does execute some inexplicable actions that aren’t in your best interests. About twice last year I contacted them and they did add a credit, I suppose it’s still a beta and that must be one heck of a complex machine learning algorithm they run, so many inputs, calculations and outputs. 

Posted by: @johnnyb

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Posted by: @papahuhu

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I find the Homely installer portal useful for checking on how Homely is controlling the system, seeing the times it is switched on, the flow temperature it sets etc.  I noticed the the COP figures it reports are very different to the figures reported by my Samsung unit so I added an elctricity meter with CT clamps on the heatpump to confirm if the Samsung kWh figures are correct. The meter is a simple unit and I don't know how accurate it is but it is quite close to the figures the Samsung unit gives.  Homely's estimate of kWh input is a lot lower meaning the COP figures are over estimated so their disclaimer at the top of the page is worth reading.

The 'heat delivered' figure matches fairly closly between Samung and Homely. I don't have a heat meter to check if they are correct but they are close enough for me to think they are probably about right.

 

Isn't there a requirement for MCS certification (or BUS grant?) that the system have a certain SCOP? Could Homely be gaming this by inflating the number? It seems a bit cynical, but the company's attitude towards data sharing makes me doubt their integrity.

Does anyone else have COP discrepancies between HP and Homely? Have any installers challenged them on it?

@odd_lion the minimum MCS requirement is 2.8.

I don't think installers are going to challenge homely on it. Why would they?

Your differential between the manufacturers controls readings vs what homely is telling you are incidentally the same as ours were. Homely would generally be around 0.5 more. So yes- my belief are that homely are inflating this number albeit any COP calculations are just an estimate.

Posted by: @benson

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Homely would generally be around 0.5 more.

Mine is a lot further out than that, for February the Samsung controller is reporting a COP of 3 and Homely is showing 4.4.  I'd be very pleased if it was 4.4

@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.

Has anyone else noticed the flow temperature being lower and the house feeling cooler, or better to say the 'hot house' feeling very unusal now?  We have UFH in a new house and the water temperature on the contoller screen used to get up to 30 or 35° but now it is mostly around 25-28°

I sent in an email 4-6 weeks ago commenting on a few things and one of them was the cool night mode not really being stuck to as the house often feels hot in the mornings. the temperature hasn't been allowed to drop and the floor is feeling quite warm even though we have a lower temperature set during the day. I did get a phone call from them but didn't feel the guy on the phone really took in what I was trying to say.

I'm wondering if they have listerned and made a few tweaks to how mine HP is running or if there has been a general update. There seemed to be comments about the hot house issue being a thing for some people with Homely and @toodles commented a few weeks back about there being trials for an update to the software.

@odd_lion 

There aren’t any input or output measuring devices associate with the homely, so it can only be performing the calculation based on the values derived from the heat pump itself. I’d imagine any deviations would be rounding errors or differences in the time period in which the calculation is covering. I’ve never seen my homely COP, but they would have to be reckless to fiddle it after what happened to the German car manufacturers.

@johnnyb 

The homely is running the weather compensation instead of the heat pump controller, so as the outside air temp increases the flow temp will be decreased as the house will be shedding heat at a lower rate. Toodles had been told it also adjusted the flow rate according to the heat demand too, not sure if that’s in response to the internal node readings or the return flow temp. It seems logical to me, I’ve noticed my outside unit sometimes stops whilst the circulation pump continues to run.

The only satisfactory solution to the hot bedrooms overnight I found was to start to use the TRVs whereas I was running full open loop. We have a very large system volume and a volumiser, so can easily afford to loose a few litres from one or two closed radiators. I haven’t noticed any adverse impact on heat pump performance yet.

@papahuhu Sorry if I have caused you to misundercontumble what I meant to write but:

As I understand it, when a Homely controller ‘takes over’ from the Daikin control system, the weather compensation is first turned off using the MMI. Homely has its’ own way of controlling the WC control. I have observed that the flow temperature varies (in my case, between 30 and 50 degrees C.) usually starting off at 40 or more degrees and dropping after a few minutes. The flow rate is, I think, controlled by the Daikin system itself and appears to be varied to maintain a fairly constant Delta T (of 5 degrees nominally).

I have observed the flow rate to be in the region of ~28-30 lpm on start up, ramping down to ~14 after several minutes then dropping to ~7 lpm thereafter and staying at this flow rate for hours usually. My system doesn’t go into defrost very often so the cycle is often on for perhaps 6-8 hours and then when warmer in the day, it may cycle after 2 hours or so. When the OAT goes above ~ 12 degrees C., the cycling period is much shorter and may stop / start 2-3 times in an hour.

Of course, this Delta T is only for the primary pipework; the secondary circuit from the LLH and on is under my control via the speed of the Wilo Pico pump. Using sensors on all 4 pipes in and out of the LLH, I have managed to obtain pairs of readings within 0.1 degrees of eachother on either sides of the LLH pipework when the primary circuit is running at ~7 lpm. As this 7 lpm seems to be the flow rate for at least 90% of the time when running, I have settled for this as probably being the most efficient setting I can obtain with an LLH in the system. Regards, Toodles.

Further to my previous posting, this plot shows today’s OAT, Flow and Return temperatures and Flow Rate. Regards, Toodles.

@toodles It was i that misunderstood. 

But, still, when I look at the data from your system, I’m struggling to see any correlation between outside air temp and flow temperature. No evidence of cause and effect, but equally possible is that on that day there  wasn’t a sufficiently large change in air temperature to initiate a change in flow temp. 
I know that with mine, if I’m standing near it, I do hear relatively frequent changes in tone, small adjustments, which suggests that something is being varied. I had always assumed it was the speed of the compressor motor being tweaked up and down.