Dutch is my first language, I can read and to a certain extent speak and write German, but I'm more fluent in English. So reply in whatever language you prefer, but I'll try English for this post.
Last two weeks we had a Vitocal 300-G installed: Vitocal 300G BWC 301.C16, two heating circuits each with a Vitotrol 200A, one heating circuit without and one with a mixer and an NC-box mounted behind the heat pump cabinet.
The engineers installing the system had several problems, some of their own making and some that were caused by bad documentation. The Vitotronic 200 type WO1C Service instruction for contractors (Dutch and German and English versions) contained at least one error and an ambiguity.
For setting the parameters for the primary source is says:
The engineers dutifully followed this instructions, but after a few days I noticed that in the diagnostics system overview I saw the icon for the Ice Buffer:
Also all parameters for the Ice Buffer and the Solar Absorber had to be entered. This was clearly wrong. Entering 0 instead of 1 for Parameter 7030 corrected this. Diagnostics now shows the icon for the brine probes as primary source and ice buffer and solar absorbers parameters are no longer visible.:
The second problem was with the connection of the mixer motor. Here it is an ambiguity: When is a 3-way valve Open or Closed. The valve mixes between 0 - 100% of the return of the circuit to the feed. As installed the mixer was set to 100% coupling return to feed when heating was required and 100% coupling secondary circuit to the feed of the heating circuit when no heating was required. Even so they had correctly followed the instruction in the documentation. Connector 225.3 to the left connector on the mixer and 225.2 to the right connector on the mixer:
Rotating the connector on the mixer solved this. The mixer manual states to rotate the connector if necessary:
A few remaining problems:
A recurring messages that says "Storing 81". A message that is not explained in any documentation I have read so far. O this forum I have gathered that the message is caused by the NC box and is presumed to be solved by a firmware update. However, the Viessmann technician has been here and has installed the latest update (4515) but he error still occurs frequently when the parameter for cooling (7100) is set to 1.
Something I do not understand is the behavior of the system in the morning. As the nights are not very cold, I set the heating circuits on standby during the night ( saves some energy on not running pumps when there is no heating required). In the morning when the system starts up it frequently overshoots the max heating buffer temperature, stops the compressor, waits 10 minutes and then repeats its behavior. Only after a couple of hours it settles down on a constant compressor power.
I would like to know how to prevent this on/off behavior.
In der Zwischenzeit habe ich einige Fortschritte bei der Untersuchung der Frage gemacht, warum sich die Wärmepumpe nach der Nachtabsenkung immer wieder abschaltet. Nach einiger Zeit bei voller Leistung tritt der Fehler 48 im Kühlkreislauf auf. Erst wenn die Systemtemperatur angestiegen ist, schaltet die Wärmepumpe auf modulierenden Betrieb um. Das beigefügte Diagramm zeigt den Verlauf der verschiedenen Temperaturen im System und den Betrieb des Kompressors. Die Werte für den Kompressor sind Näherungswerte, die sich aus der Leistungsaufnahme der Wärmepumpe ergeben.
