imautohuttraeger wrote: Sunday 25 October 2026 0:17
This is the follow up of an off-topic discussion with @Ragdag in another thread.
viewtopic.php?p=336185#p336185
So let me outsource it to this separate topic. I am looking for a solution for a simple user like me to get data from my Wolf CHA07 heatpump via the communication module ISM7i. I notify hereafter my answers to questions, that @Ragdag already asked me:
Which Wolf network modules do you have: Link Home, ISM7i, ISM8i, or none?
-> ISM7i
Which CHA do you have (07 or 10), with or without cooling, and are there other Wolf parts connected (BM-2 control module, mixer modules, solar, ventilation)?
--> CHA07 with BM-2 control display module
Which values would you most like to see in Domoticz?
--> actual power, consumed energy, amount of heat produced, number of cycles (compressor starts).
Which Domoticz version are you running?
--> currently 2026.4 (build 18479) beta or latest beta
When you tried ism7mqtt, do you remember where it got stuck?
--> Not really, it is more than one year ago. There where error messages in Linux (Raspi) even before I could get further.
Do you already have an MQTT broker running (for example Mosquitto)?
--> Yes, Mosquito is running and receiving data, for example via MQTT auto discovery
What does your Raspberry Pi show when you run this command in a terminal? That tells me which version you need.
--> armv7l
Is Docker installed on it? (No problem if not.)
--> No, Docker is not installed.
Do you use the Wolf Smartset app regularly, or could you live without it?
--> I use it regularly and I don't need to control the heat pump via Domoticz. My installing company is also using it for remote maintenance if necessary.
Do you know the password of the ISM7i?
--> Yes, I have the password.
Thanks for the complete overview, that helps a lot. One of your answers is important, so let me start with that.
The catch: the ISM7i accepts only one direct connection
The ism7mqtt documentation says the ISM7i accepts only one connection at a time, so while ism7mqtt is running, the Smartset app cannot connect directly to the module. That is a limit of the ISM7i itself, not of ism7mqtt, so a Domoticz plugin would run into exactly the same thing.
What I could not find out is whether the Smartset app via the Wolf cloud keeps working, both for you away from home and for your installer's remote maintenance. That goes through the internet instead of directly to the module, so it might be unaffected, but nobody documents it. For you that is the deciding question.
Your old error messages
There is a known problem with ism7mqtt on newer Raspberry Pi OS versions: the connection to the ISM7i fails with an SSL error right at the start. There is a fix for it (a small change to a settings file), so that may well be what stopped you last time. For your Raspberry Pi (armv7l) there is a ready-made version, so nothing needs to be built.
A possible next step
The only way to answer the cloud question is to try it: run ism7mqtt for a short while, check in the Smartset app over mobile data (Wi-Fi off) whether you still get in, then stop ism7mqtt again. Stopping it puts everything back as it was. If the cloud keeps working, ism7mqtt can stay running and we can connect it to Domoticz. If it does not, this route is not an option for you, and I would rather know that before you spend an evening on it.
Also good to know: other users report that changes can sometimes arrive a few minutes late, so this is fine for power, energy and starts, but not for second-by-second monitoring.
If you want to give it a try, I'd like to get the preparation right in one go so we don't have to go back and forth too much. Could you run the commands below on the Raspberry Pi and post the complete output? They only read information and change nothing.
Replace 192.168.1.50 on the first line with the IP address of your ISM7i:
Code: Select all
ISM7=192.168.1.50
cat /etc/os-release
uname -m
getconf LONG_BIT
ldd --version | head -n 1
openssl version
ldconfig -p | grep -E "libicu|libssl"
free -h
df -h ~
ping -c 3 $ISM7
for p in 9092 9091; do timeout 3 bash -c "</dev/tcp/$ISM7/$p" 2>/dev/null && echo "port $p open" || echo "port $p closed"; done
And a few questions:
- Do Domoticz and Mosquitto both run on this same Raspberry Pi? If not, what runs where?
- Does Mosquitto need a username and password? (Just yes or no, please don't post the password.)
- In Domoticz, open your MQTT Auto Discovery hardware: what is filled in as the "Auto Discovery Prefix"?
- Does the ISM7i always get the same IP address (fixed in your router), or can it change?
With that I can write the steps for your exact setup.
