Custom Controller for Ventomaxx Home Ventilation System and Home-Assistant Integration

A dumb wall controller was replaced with a custom ESPHome controller to gain full Home Assistant control, per‑room fan control, and automations for quieter nights and smarter operation. The system keeps the original alternating 70‑second pendulum cycle used by decentralized heat‑recovery fans.

2025-09-07 · Tom Beyer

Modbus adresses heatpump 'iDM Terra ML Complete HGL'

I got the request of a visitor to publish the modbus adresses I use to read from my heatpump. I asked iDM if iam allowed to publish the adresses and they agreed. So here they are: # Dec. Hex. Type Description Unit 01 1000 3E8 FLOAT Außentemperatur °C 02 1002 3EA FLOAT Wärmepumpen Vorlauftemperatur °C 03 1004 3EC FLOAT HGL Vorlauftemperatur °C 04 1006 3EE FLOAT Wärmequellenaustrittstemperatur °C 05 1008 3F0 FLOAT Wärmepumpen Rücklauftemperatur / Wärmespeichertemperatur °C 06 1010 3F2 FLOAT Kältespeichertemperatur °C 07 1012 3F4 FLOAT Trinkwassererwärmertemperatur °C 08 1014 3F6 FLOAT Frischwasserzapftemperatur °C 09 1016 3F8 FLOAT Heizkreis A Vorlauftemperatur °C 10 1018 3FA FLOAT Heizkreis B Vorlauftemperatur °C 11 1020 3FC FLOAT Heizkreis C Vorlauftemperatur °C 12 1022 3FE FLOAT Heizkreis D Vorlauftemperatur °C 13 1024 400 FLOAT Heizkreis E Vorlauftemperatur °C 14 1026 402 FLOAT Heizkreis F Vorlauftemperatur °C 15 1028 404 FLOAT Heizkreis G Vorlauftemperatur °C 16 1030 406 FLOAT Heizkreis A Raumgerät °C 17 1032 408 FLOAT Heizkreis B Raumgerät °C 18 1034 40A FLOAT Heizkreis C Raumgerät °C 19 1036 40C FLOAT Heizkreis D Raumgerät °C 20 1038 40E FLOAT Heizkreis E Raumgerät °C 21 1040 410 FLOAT Heizkreis F Raumgerät °C 22 1042 412 FLOAT Heizkreis G Raumgerät °C 23 1044 414 FLOAT Heissgastemperatur °C 24 1046 416 FLOAT Feuchtesensor % r.F. 25 1048 418 FLOAT Luftansaugtemperatur °C 26 1050 41A FLOAT Luftwärmetauschertemperatur °C 27 1052 41C FLOAT Solar Kollektortemperatur °C 28 1054 41E FLOAT Solar Ladetemperatur °C 29 1056 420 FLOAT Solar Kollektorrücklauftemperatur °C 30 1058 422 FLOAT Solar Wärmequellenreferenztemperatur / Pooltemperatur °C 31 1060 424 FLOAT Gemittelte Aussentemperatur °C 32 1062 426 FLOAT Wärmequelleneintritsstemperatur °C 33 1064 428 FLOAT IDM Systemkühlung - Ladefühler Kühlen °C 34 1066 42A FLOAT IDM Systemkühlung - Rückkühlfühler °C 35 1068 42C FLOAT Wärmemenge Wärmepumpenvorlauf (bei Navigator 1.0) kW 36 1070 42E FLOAT Wärmemenge HGL-Vorlauf (bei Navigator 1.0) kW 37 1072 430 FLOAT Wärmemenge Momentanleistung kW 38 1074 432 FLOAT Wärmemenge Solar kW 39 1076 434 FLOAT Wärmemenge gesamt (bei Navigator 1.0) kWh 40 1078 436 FLOAT Wärmemenge Heizen gesamt kWh 41 1080 438 FLOAT Wärmemenge HGL gesamt (bei Navigator 1.0) kWh 42 1082 43A FLOAT Wärmemenge Kühlen gesamt kWh 43 1084 43C FLOAT Wärmemenge Solar gesamt kWh 44 1086 43E FLOAT Summe Durchflussmengenzähler Grundwasserpumpe (bei TERRA SW Max mit Navigator 1.7) 45 1088 440 FLOAT Betriebsstundenzähler Wärmequellenpumpe (bei Grundwasseranlagen) 46 1500 5DC UCHAR Aktuelle Störungsnummer 47 1501 5DD UCHAR Betriebsart Wärmepumpe (0=AUS / 1=Heizen / 2=Kühlen / 4=Vorrang / 8=Abtauen) 48 1502 5DE UCHAR Status Heizkreis A 49 1503 5DF UCHAR Status Heizkreis A (kein Heizkreis B bei Navigator 1.7) 50 1504 5E0 UCHAR Status Heizkreis C 51 1505 5E1 UCHAR Status Heizkreis D 52 1506 5E2 UCHAR Status Heizkreis E 53 1507 5E3 UCHAR Status Heizkreis F 54 1508 5E4 UCHAR Status Heizkreis G 55 1509 5D5 UCHAR Status Verdichter 1 (0=Aus / 1=Ein) 56 1510 5D6 UCHAR Status Verdichter 2 57 1511 5E7 UCHAR Status Verdichter 3 58 1512 5E8 UCHAR Status Verdichter 4 59 1513 5E9 UCHAR Status Ladepumpe (0=Aus / 1=Betrieb / 2=Störung) 60 1514 5EA UCHAR Status Wärmequellenpumpe 61 1515 5EB UCHAR Status Zwischenkreispumpe 62 1516 5EC UCHAR Status ISC Kältespeicherpumpe 63 1517 5ED UCHAR Status ISC Rückkühlpumpe 64 1518 5EE UCHAR Anzahl laufende Verdichterstufen Heizen gesamt 65 1519 5EF UCHAR Anzahl laufende Verdichterstufen Kühlen gesamt 66 1520 5F0 UCHAR Anzahl laufende Verdichterstufen Vorrang gesamt 67 1521 5F1 UCHAR Betriebsart Kaskade 68 1522 5F2 UCHAR Betriebsart Solar 69 1523 5F3 UCHAR Smart Grid Status 70 1524 5F4 UCHAR IDM Systemkühlung (ISC) Modus

2019-01-02 · Tom Beyer

Wallmounted Home Assistant Dashboard

I have long wanted to have tablets on the wall of the ground floor and upper floor where I can control Home Assistant. In the last Black Friday Sale I bought two relatively cheap 10 inch Fire Tablets from Amazon for 99€ each. The only difficulty was to supply the tablets with electricity. But then I came up with a very practical solution. Qi Charging Pad I bought a Qi Micro USB Ladepad at Amazon (Afiliate Link): ...

2018-12-29 · Tom Beyer

Home-Assistant integration of 'Abfall.IO' waste collection dates

I wanted the garbage collection dates on my HA dashboard. Unfortunately, the city of Landshut doesn’t offer an API to access them directly. So i wrote a custom integration.

2018-11-20 · Tom Beyer

Home-Assistant integration of heatpump 'iDM Terra ML Complete HGL'

I switched my home automation system from OpenHAB to Home-Assistant and am very happy with the decision so far. Of course, I also had to change the integration of my heat pump. Therefore I developed my own module for Home-Assistant. Result The result looks like this: Lovelace Lovelace iDM heatpump I also visualized the values in Grafana which looks like this: Heatpump in Home-Assistant Lovelace Grafana Grafana visualization of heatpump data ...

2018-10-02 · Tom Beyer

Connecting my heatpump 'iDM Terra ML Complete HGL' to OpenHAB 2 using MODBUS via node-red

For some time now I have been using OpenHAB at home for the central control of my house. In OpenHAB, for example, I manage shading, control some lamps, measure and visualize the energy consumption of certain consumers such as refrigerators or washing machines. The biggest consumer in the house I have not connected yet, my heating. This is a Terra ML Complete HGL heat pump from iDM. A little research on theire website has shown that the key figures of the machine can be read out via TCP (i. e. Ethernet) via the MODBUS protocol. ...

2017-12-15 · Tom Beyer

Converting the cheap Anet A8 3D Printer to a DIY AM8 Aluminium Printer

Initial build of the Anet A8 upgrade I started to upgrade my Anet A8 to proper aluminium extrusions. Iam using the fantastic project called AM8. I started with my intial build: Finalizing the mechanical part This weekend in finished the mechanical part of the upgrade of my Anet A8 to to the aluminium AM8. Next step is finishing the electrical installation and setting up the firmware. ...

2017-06-24 · Tom Beyer

VORON 1.5: Building my DIY 3D Printer

The build begins & tapping aluminium extrusions I ordered the wrong size self-tapping screws (M5 instead of M6), so i had to tap the aluminium extrusions manually. I changed my BOM so nobody else has the problem. Installing frame & motors + first problem Today I finally installed the frames and mounted the motors. Also wanted to mount the A&B idlers but unfortuneately the steel dowels have an diameter of 5mm and the inner diameter of the flanged bearings have an inner diameter of 4,96mm. ...

2017-02-15 · Tom Beyer

DIY Lab Power Supply – DPS5015 – 360W

Self made Power Supply, based on a DPS5015 module from AliExpress.

2016-11-20 · Tom Beyer

Rancilio Silive PID upgrade

When i got 2015 my new espresso machine I had quite some problems with the fluctuating temperature of the boiler. So I decided to replace the bimetal thermostat with a PID controller. I installed the controller in an external plastic box, so I didnt had to cut any holes in the machine (just in case I want to sell the machine). Second modification was adding a cheap LED lightsource. Pictures Dismanteled 1 ...

2015-07-18 · Tom Beyer