Daikin EKRHH home hub local modbus integration

gerione · September 28, 2025, 7:13pm

You need to manually add the repository. Custom Repositories - HACS. GitHub - gerione/daikin-ha-ekrhh-modbus: Modbus connector for the ekrhh home hub

gerione · September 28, 2025, 7:16pm

Power limit will be configurable on the next version. Probably in one week

dave5 · October 31, 2025, 7:46pm

Hi @gerione,

Great work here, investing so much time to give to the community.

I have just bought a Daikin altherma 4 air/water heat pump(the combination EPSX10P50A-EPSK08AW1). Based on some googling and your post here I looked into the Daikin home hub (ERKHH) to connect HA>your integration>EKRHH>EPSK08AW1 though nowhere found documented that those components are compatible. In my search I eventually ended up with a very friendly guy from Daikin Netherlands who told me that for the Altherma 4 no EKRHH is needed (and not even compatible anymore) Instead the indoor part (EPSK08AW1 in my case) is able to talk modbus directly.

So that sounds great, one less moving part, and over 300 Euro saved! I got the interface specs from him which for unknown reason is not documented anywhere online. Quickly glancing over it, it seems to match the modbus spec of the EKRHH. with a bit of luck i should be able to just point your integration to IP i am getting from the heatpump once i have it connected.

here a screenshot

or would that be too optimistically?

Next week all gets installed so as soon as the thing is powered up i’ll connect it, of course will share here.

Anyone else having experience in connecting the Altherma 4 heatpump of Daikin?

jonhummel · November 1, 2025, 10:01pm

Hi Dave, Jon overhere (also from the Netherlands). The Altherma 4 will be installed mid december at our side. I was also researching the HomeHub, Daikin answered that the hub will be available july 2026. For me it is also far more interesting to use the modbus directly like you have found out.

Would it be possible to share the complete list?
And just a question; is connecting the Altherma 4 via LAN with my network sufficient for using modbus… or do we need to use P1/P2 ports or something like that?

Jmi · November 5, 2025, 8:29pm

Hello,

I intend to purchase the Daikin Altherma 3R EHVH08S23E6V. From my understanding, using this integration and the EKRHH would be the simplest way to integrate it in HA. Would someone be able to confirm please ?

dave5 · November 13, 2025, 9:44am

Hi Jon,
I am still quite busy with the new house. Also the heat pump has unfortunately issues (self inflicted i am afraid). for now i will share the holding register that i worked on. the rest of the excell contains personal comments from Daikin people which i can imagine is not for public consumption. in th epdf print of one of the tab of the excel i have:
marked RED > registers that AL4 (altherma 4) is not using anymore (compare to EKRHH)
marked yellow > NEW registers that AL4 is using (and where not there in EKRHH)

aim is to complete the full spec (so also input, coil etc) of what is the difference between this integration and the changes that would be needed to make this integration integrate directly into the altherma 4.

note; my EPSX10P50A is 90% ready, next week the installer comes to finish (i hope). I already found an RJ45 connection almost hidden on the circuit board.

dave5 · November 13, 2025, 9:48am

dave5 · November 24, 2025, 2:47pm

yes, i think the same. you can check the installer reference guide here for info on compatibility and more https://www.daikin.eu/content/dam/document-library/Installer-reference-guide/heat/accessories/ekrhh/EKRHH_Installer%20reference%20guide_4PEN744838-1D_English.pdf

Timo_Beil · December 28, 2025, 12:13am

This document shows the complete table of registers at p. 266 ff (german). The position of the RJ45 jack ist shown at p. 154 ff.

Oleg1610 · January 25, 2026, 10:39am

Hi @Gerione,
thank you for your work on the EKRHH integration.

I am using a Daikin air‑to‑air system with two outdoor units and five indoor units (Use Case 4).
In this setup, I have a question about the Power Limit for Demand Control:

Is there a plan to support writing this value from Home Assistant in a future version?
I would like to use it for a temperature‑based control.

If there is already some information about this, I would appreciate a hint.

gerione · January 30, 2026, 8:00pm

Hello everybody.
I just finished the work on a complete backend overhaul.
This should now allow for the use of an Altherma 4.

@Oleg1610: This version also should work with the air-to-air system and writing should be possible.

Maybe somebody can test the alpha version: Release 1.0.0 - Altherma 4 and backend overhaul · gerione/daikin-ha-ekrhh-modbus

jaholm42 · February 16, 2026, 6:01pm

Hi Gerald,

I’m using 0.5.3 in many of my automations and I’m very happy. Thank you for this integration.
Your new version 1.02 change may entity ids so the simple way is search and replace in automations.yaml. But I cannot find a list of new entity ids in your code on github. Maybie they where genertated.
I would like to know which entity I need to replace with which new one.
E.g. what is the replacement for number.daikin_ekrhh_dhw_reheat_setpoint ?
Is there a simple schema?

Danke!

gerione · February 20, 2026, 10:14am

Hy.
at least in my case its naming stayed the same, after i did the following steps:

Install new version
Restart
Go to the Integration page
Go to three dots and entities
Remove no longer provided entities
Go to three dots and select recreate entity IDs

christophgellert87 · May 7, 2026, 7:55am

Guten Tag zusammen,

ich bin über diesen Beitrag gestolpert und möchte mich mit meinem Anliegen gerne einklinken und hoffe auf etwas Hilfe.

Ich habe ebenfalls eine Daikin Altherma 3 M (Monoblock, EBLA09D3W1), die ich gerne in Homeassistant einbinden möchte.

Folgende Infos kann ich vorab liefern:

Innen im Keller habe ich nur das Bedienteil, Software-Version 7.8.0, angeschlossen 4-adrig an Außeneinheit (+/- 12 V & P1/P2)
WLAN Modul (diese kleine Karte) steckt im Bedienteil
-> darüber Cloudzugriff über die Onecta App

getestet hatte ich bereits die Daikin Onecta Integration für Homeassistant, diese liefert aber kaum bzw. keine weiteren Möglichkeiten der Steuerung, genauso wie die App.

Daher habe ich mir nun den Daikin HomeHub (EKRHH) zugelegt, Modbus Steuerung via TCP. Und daran scheitere ich aktuell.

Der HomeHub ist mit 2-adrigem Kabel an P1/P2 des Bedienteils angeschlossen, ist also dort durchgeschliffen. Und hängt via LAN in meinem Netzwerk. Ich habe in Homeassistant die HACS Modbus Integration (daikin-ha-ekrhh-modbus) installiert. Der HomeHub ist erreichbar, auch die Onecta App erkennt diesen als neues Gerät.
Die Integration liefert aber keine Werte, sondern bei den Sensoren steht "Nicht verfügbar".

Die gennanten Tipps helfen mir alle nicht weiter.

Es scheint, als müsste man den HomeHub bzw. Modbus im Bedienteil explizit erlauben. Aber: in meinem Bedienteil gibt es nirgends den Menüpunkt "HomeHub", auch nicht in den Monteureinstellungen. In der Onecta App ist "Modbus Einstellungen" ausgegraut.

Ich habe bereits alles ausprobiert.

Gerät reset
Wärmepumpe stromlos um einen Scan der Modbus Geräte zu erzwingen
Anschlüsse getauscht
WLAN modul entfernt

nichts hat geholfen.

KI gefragt... angeblich ist Modbus gesperrt und muss manuell freigegeben werden. Das kann ich aber nirgends tun. Obwohl meine Software aktuell ist.

Hat jemand den HomeHub im Einsatz und kann weiterhelfen?
Ich bin für jeden Tipp dankbar.

VG
Christoph