Yes you are right. Maybe I had an unstable connection. But now it works. The script works very well and I get the data. The only pity is that the shortest sequence is the daily consumption. This means that an evaluation over the day is not possible. But at least a long-term evaluation works with it. I now add up the daily consumption to a total counter and compare this with the real water meter. I am curious whether these match or whether I have to calibrate the daily consumption sensor as a template sensor.
I’ve got an error if I put that in my configuration.yaml. Here’s how I avoided it:
command_line:
- sensor:
name: gruenbeck
command: "/usr/local/bin/python3 /config/gruenbeck.py"
json_attributes:
- code
- durchfluss
- restkapazitaet
- restdauer_wartungsintervall
- seit_regeneration
- regeneration_progress
- wasserverbrauch
- anlagenkapazitaet
- salzreichweite
- aktueller_regenerationsschritt
- restdauer_regeneration
value_template: "{{ value_json.code}}"
scan_interval: 1800
confirm. had also to change it (back in june ?). Home Assistant made some changes in the syntax 
Hello Together,
I have also a SC18 running since 2017. I had quite a long journey integrating this in openhab then with scrape plugin in HA, and finally with this script. I had always issues with the stability, as Gruenbeck has his restrictions and drawbacks in the mux api. Now I found some time to create a custom HACS Integration.
I just started, adding my favorite sensors and all i found out there.
I added also some goodies like showing the last error message 
Would love to add further thinks like switching the mode from ECO to Power.
Currently this is tested only with my SC18 would love to get some feedback if this works also for others.
Feel free to also add