Daikin Altherma, ESPAltherma with Eddi and Smart Grid

I got my Octopus Daikin heat pump installed last week, and have just discovered this thread and working through what I need to do to set it up. It is very informative and I’m just waiting for it to stop raining to open up the monobloc.

I will start of with trying to install the ESP inside the monobloc and see if the wifi signal is good enough. For the independent energy monitoring, I’m not sure which live it need to go around. In the garage (where I already have a Harvi) I have the consumer unit which takes the mains power from a henly block and I can see the live cable there, but in the back garden I also have a second consumer unit which I think (I can get photos tonight) has two cables going to the heat pump, one for the pump and one for the booster/immersion power?).

If it’s the unit in the garage then I can easily run a new CT clamp to the Harvi (what should I set this to so it doesn’t mess with the displays in the Myenergi app). If it’s the consumer unit in the garden then I will need a Shelly.

Lastly, I know this thread is specifically about OEM and ESP but I’ve not had much luck in the forums. As we had an Eddi, we are using that to control the immersion and the legionella cycle, and have turned this off in the MMI. I have seen there is a way to use the relay in the Eddi to connect it to the heat pump, but the installer didn’t know how to do this, as there wasn’t a suitable connection in the monobloc, but they left a spare cable run incase it can be worked out. Has anyone in this thread got this set up?

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Hi Chris,

The setting you are looking for is called smart grid on the Daikin units and octopus set this up but I had to get all the schematics and talk the electrician and the head of electrical services through it (as it is not something they normally do).

I have a document outlining the basics here but let me know if you have any questions.
Settings for Daikin ASHP - Eddi smart grid integration .pdf (49.9 KB)

I wonder if I can get the electrician from the job back, they seemed quite keen to get it working but didn’t have enough info at install, so just left the cables.

Do you have a photo of the inside of the Eddi as there are more connections there than I expected. Also where do the CT clamp for the pulse meter go?

You can try asking but electricians at octopus are in high demand (heatpumps, EV chargers and smart meter swaps etc.), if it was not on your contract you may need to get another sparkey in to do it.

The data / pulse output connections from the pulse meter (CT clamp onto main incoming cable) go directly to the heat pump and this is what allows it to modulate and only use what you have as excess. If you don’t want to use this you can manually set a limit but this may end in you importing electric.

The images of the connections in my Eddi can be seen below.

Getting the CT to the incoming mains from where the heat pump is will be my biggest issue.

Edit: I have a OB115 as part of my Givenergy battery install so I could maybe wire in from that?

If the unit is currently is inline with the mains supply or on a CT clamp then provided this is on the mains supply that will be fine. You just need a pulse meter output to feed into the heat pump.

Do get an electrician to do this or be sure to isolate all supplies before looking at it.

You can always run the cable in advance in ducting to make this easier on install day. Just leave it disconnected at both ends.

You will still need a way to get the signal from the meter to the heatpump as the connection for this is inside the outdoor unit.

The heat pump is already installed. The electrician left a spare cable run from the hot water cylinder to the heat pump which is either 4 or 6 core, so I have what I need to connect the Eddi to the heat pump. I just need the 2-core from a pulse meter.

Can I just check how it works in this set up? I’m expecting the Eddi can monitor for solar excess and trigger the immersion heater, but the heat pump can also make a call to override the Eddi to run a legionella cycle when required? At the moment the Eddi is essentially decoupled from the heat pump (I think it just gets the power supply from the control box inside), so the heat pump doesn’t have the booster (powerful setting in the app) enabled.

I’ve also in the past couple of days got the ESPAltherma running on an ESP32, I just need to add a monitor to get the energy draw from the heat pump to be able to calculate my COP.

We have an Eddi connected to the immersion heater, and Octopus didn’t make any connections to the heat pump. I don’t know if there are any spare cables…

@KnightPhoenix - can you explain what the smart grid settings are for, and why a pulse meter is required?

I had assumed that when the heat pump runs a legionella cycle it would get the tank up to 50C (say), then close the contacts connected to the Eddi relay board, causing it to run the immersion heater, and when the 60C is reached for the required period it stops the Eddi.

(@Timbones maybe Eddi / Daikin integration could be forked to a new thread?)

Done! :slight_smile:

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@ChrisG3, @squarepeg77

From my understanding the Eddi basically becomes a smart relay.

So the Eddi detects what is being exported to the grid (house usage and topping up a battery would take priority and are not counted). Once the export is above a set level (including or excluding what is going to the immersion depending on the “include diverted” setting), then the relay for the smart grid is activated, this will tell the ASHP to run and use excess electric to firstly overheat the DHW tank to the maximum temperature, Then if room buffering is enabled increase the heat of the house up to the comfort setpoint. (this is covered in the Daikin installer reference guide, all be it a bit al over the place) Daikin call this setting “Smart Grid”.

The pulse meter on the incoming mains tails sends out a pulse signal that the heat pump then uses to limit / range rate the current usage of the unit to only use what is being exported (if you are exporting 800w of solar to the grid, the ASHP will only use 800w and not run at full power for the DHW or room buffering). Alternately you can set static power limits in amps or watts and this is mentioned in the reference guide, be aware though if you set this to say 2kW, that this may mean you are exporting 800w and using 2kW to overheat DHW (not the best use of electric).

With regards to the Immersion you would also wire up the immersion wire from the ASHP to the e~sense port on the Eddi (as mentioned in the word doc) and then setup the boost function to activate when 220 - 240v is sensed on this port (this is only sensing the presence of voltage and not actually taking any current from the ASHP). This will then via the configuration on the Eddi trigger the immersion heater to run at full power regardless of any solar input.
This allows you to set legionella cycles and boost the hot water on the Madoka (Daikin controller) and allows the ASHP to have full control of the immersion heater while still keeping all of the smart features of the Eddi.

The wiring is covered in the word document and the initial configuration on both the Eddi and the Madoka is also listed. As mentioned My installer has done this for me so Octopus have previously done this and it does work.

With regards to ESPAltherma, it is ok but remember the Daikin meters are not as accurate as MID metering and any changes or manipulation to any figures will show on the portal (for example I see one Daikin with about a 30% lower electric usage compared to every other unit so the SCOP looks great but that sort of SCOP will not reflect in your actual billing due to the laws of physics). Not sure if that is due to the Daikin meters being that far off or if some data manipulation is occurring in HA for some reason or another but something to think about. A SCOP of 12 on the chart is not relevant if you are still only actually getting 2.6 in real life.

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Amazing that’s is super helpful, I will try and get Octopus back.

I will look to get a separate Ct clamp to read the heat pump energy usage. I was hoping I could piggy back off a Harvi but it’s in the wrong position.

So for my install, Octopus installed two separate plastic consumer units outdoors.

One by the meter cupboard - this contains the ob-115 for the mains power export metering (with a split CT clamp) and has a two core cable for the pulsed output feeding back to the ASHP.

The one by the ASHP - This contains the SDM230ModBus meter (metering the energy usage of the ASHP) with a three core cable going up to the airing cupboard where I have the modbus-usb adapted directly into my EmonHP (OEM heatpump l3 kit) You could also plug this into a HA unit or into any other PC and just configure the readings to direct to Emoncms.org. This is a bit more expensive but would ensue MID certified electricity readings.

To get the heat meter is expensive (that’s just what they cost) but would allow you to have very accurate flow and heat output readings and a very reliable COP. Just depends how much you are interested in the figures being accurate and using them to tweak the system / highlight issues or if you just want an approximate guess at the COP / what’s going on.

I work in the tech industry and am very data driven so the £600 was the only choice for me, Octopus did install for an extra £200 (in April 23) but I am sure if you spoke to the right people from the install team and plied them with coffee / biscuits and maybe a pizza for lunch they may be willing to pop it in for you (not sure they would be interested to install after the event but nothing ventured i guess). This kit also clearly showed some major issues with our install and ended up with Octopus basically swapping out the heat pump, changing more radiators and re piping the upstairs to correct these (if you look at my stats you can see steps in October and January in COP).

Just remember all of this is possible as you can have a separate sparky and plumber come and retrofit and you can run extra cables / conduit but it just depends how much you want to spend, how much disruption you want (we installed underground ducting to hide the cables and had to dig up the driveway) and what your goal of all of this is.