I have the (Daikin EDLA09D3V3) and looking through different forums it seems to be the one people have a lot of trouble with. I have been complaining to Octopus for a long time about the poor results the HP gives and the amount of adjustments I have to make. At the moment they say, as I am not running the HP as per the contract ( I have taken the WC down to 39 @ -3 ) they will not accept any complaint. I have now put it to the 50 @ -3 as per contract so see how things go. Due to fluctuations in temperatures I am almost running the HP as a gas boiler. Has anyone had problems with the weather compensation setup as I am sure it is not responding as it should.
What is it doing or not doing that you think it shouldn’t or should? It’s hard to make suggestions unless you describe your problems!
Hello John, thanks for taking the time to respond. I’m away this weekend but il do a drawing or take a photo. But In basic terms the main power feed has a CT clamp round it, so I’m not monitoring the backup heaters independently just the power into the external fuse board. In regards to the unit. Silver with a black fan cover.
Thanks for reply. HP purchased in August 2022. During the following winter I complained to Octopus that the property was not heating to spec. The changed the radiators in bedrooms, increasing the size. However I have been in contact with Octopus numerous times since about the level of heating. Engineers visit but really do very little in improving the situation. Have always been of the opinion that the thermostat was placed in wrong position (hallway in small area and always goes over the selected temperature. This morning was set to 20C but was still operating at 21.5C, (however the bedrooms were just above 16C and living room 18C - they were calculated at 18C and 21C) The weather compensation sensor was placed on north facing wall ( I know it should not be directly in the sun) but I think the sensor is over compensating for outside temperature.
I have attached some photos showing the settings for the HP.
Any thoughts to improve setup would be helpful.
@dmhom why is the heat pump off for 8 hours between 6pm and 2am, and off again during the morning?
During these cold spells, we’ve got ours running from about 3am, right through to 10pm. Other people here run their heat pump 24/7.
Heat pumps run more efficiently if they dribble heat into the house to match the heat loss. They don’t work well when asked to rapidly bring the house up to temperature.
You will probably get better efficiency running the heat pump for more hours of the day, but at lower temperatures.
Also do you have a thermometer that you can use to measure the radiator temperatures? It’s worth checking they are close to what the heat pump flow temperature is, and that they are balanced somewhat correctly.
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My schedule is 03.00 - 21C, 05.30 - 20C, 15.00 - 21C and 21.00 - 19C.
The pump was running to after 8pm but was at low output. Not sure why went off after this.
It is the idea to run the pump continuously at low temperature but if the Madoka thermostat has reached set temperature the pump will turn off. As this pump never goes below 900 - 1200w it can become rather expensive running 24 hrs.
I manage to keep my costs down but this is because I have 2 batteries, solar panels and am on IOG tariff.
My inclination would be to switch to pure LWT control, since the thermostat is not providing any useful input. You could then adjust the WC settings so that the house is the temp you want, without the added complexity of the ‘stat. Once that’s dialled in, maybe look at using the ‘stat if you need it but…
My thermostat is in a truly stupid place so I had to do this from the start. It’s still not in use, and my house is warm. I do however have the heating on all the time, it only goes off when the outside temp gets above 14c. I did have a 2c setback schedule overnight on the LWT, but it didn’t make enough difference to energy usage to make it worthwhile!
Jon’s suggestions are pretty useful too. Lots to try!
What are you using to collect the data you provide? OEM gear or something like ESPAltherma?
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If your rooms are too cold - and that is what you want to fix first - then running the heat pump for more hours of the day is a good start.
From your screenshots, it’s clear the heat pump is pulling over 3kW in some one hour periods, so you could get 3 hours of minimum power operation for the same kWh usage.
PS: @dmhom your SCOP of 3.23 isn’t too bad. My 9kW system has returned 3.30 since December 2023. John’s has delivered 3.35.
But I firmly believe running the heat pump for more hours per day will deliver better efficiency and probably won’t use any more electricity, as the system will get into the lower power steady-states. Currently your system is running hard for only part of the day.
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@John @squarepeg77 thank you for feedback most useful.
@John I had the Level 3 Heat Pump Monitoring Bundle (emonHP) installed by Octopus.
@John Can you clarify setting the system for LWT. If you switch the Madoka off I understood it turned the HP system off as it was wired through this. In the MMI there is an option ‘Room Thermostat or External Thermostat’ is there another option to have no thermostat. or can I do it another way.
You can either
- set the Madoka as high as it will go, to a level it won’t get to, so it is effectively always on, or
- you can go to the MMI, put it in installer mode (5678) and set Setpoint Mode on main zone to LW only (not room or external room stat), and also Weather dependent.
I don’t have the manual in front of me! It will restart and then you put it back in user mode.
If pushing Madoka up make sure modulation is disabled…
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Hi Derek @dmhom
In my view, the 1st thing to do is to work on reducing the frequency of defrosts which is killing your CoP.
It’s an unfortunate habit of the Daikins that they go hell for leather at the start of a cycle to get the flow temperature up to target and having the pump working hard at these times encourages the next lot of frost to form - and because the machine is not learning from its experiences the next defrost inevitably follows.
Bearing in mind that you’ve said that your property doesn’t need all the power of your pump (much the same as a lot of us) the question is how to adjust the MMI settings to get the pump working less hard?
What has worked for me and my 8kW Daikin is to set lots of parameters as low as possible:-
| MMIbreadcrumb | description | value | notes |
|---|---|---|---|
| 1.7 | room sensor offset | 1 degree | makes Hall display similar to emonTH |
| 2.5 | WD curve | 36@-2 35@12 | |
| 2.7 | emitter type | Radiator | |
| 2.8.1 | 25 degrees | ||
| 2.8.2 | 65 degrees | ||
| 2.B.1 | target DT for CH | 10 degrees | set so wide that it can never be achieved - to keep the flow rate very low. |
| 2.C.1 | No Modulation | ||
| 2.E | WD curve type | 2 point | |
| 4.5 | Pump mode | Request | |
| 4.7 | Pump limitation | 70% | |
| 7.4.3 | Quiet mode | Most Quiet | puts further limitations on pump agility. |
| 8.6.2 | Defrost / Oil return | off | this is an information field. Not sure what it means. |
| 9.2.1 | DHW tank type | 3rd party small coil | selected to reduce power going into tank coil. |
This example shows my pump in defrost territory but managing to break out of getting into a loop. I think this is because of the modest workload required of it in those conditions. Notice that the flow rate reduces shortly after the start of a cycle - perhaps because the pump is trying to respect meeting the specified wide DT.
This system has a design heat loss of 7.5kW and 50C flow at -2 degrees outside, but I find that my rads can support being driven as cool as shown in my settings. My typical heatpump output (3kW) is enough to keep my house at a steady, comfortable temperature.
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there is also a maximum input setting in the mmi some where which can help
Reports as ON during a defrost
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I’ve been pondering scripting some active intervention to aid recovery from a defrost. My heating system creaks quite a lot when the temperature changes, so I’m usually alerted to a defrost happening. When I notoce, I typically drop the requested LWT several degrees manually (through MMI or app), and then gradually raise the target as the water temperature rises.
I have enough bits and pieces in place to put together a script to automate this through the API, just haven’t got round to it yet.
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Thanks for that info. Unable to see if you use LWT or the Modaka thermostat. Have been thinking about changing my emitter to radiator.
Thanks @John @meatballs @dmajwool, have changed my Control to LWT, Modulation is dimmed so I assume it is unavailable and the Madoka is on and shows a temperature. The plus/minus buttons on the Madoka do not change the temperature as before but give you a plus or minus figure?
The DT in MMI is set at 5, do I need to alter this figure? Have set WC to 45@ -3.
Great! The ± is offset from current calculated LWT value at whatever ambient temp outside. So you can set it to -2 for example as a simple means of seeing if that LWT value is sufficient. The dT is independent, so if you want to try @dmajwool’s defrost approach you can. Might be better to get it in the zone with the WC first…
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Why can’t this be done wherever the LWT is more then a few degrees below target others then when full output is needed?