My one of my 12Kw Vaillant Arotherm is short cycling every 10 minutes when ambient reaches 11 degrees. Both HPs operate normally below 11C. There are 3 zones set Inactive. The system volume is circa 400+ litres. The pipe run from the 2 HPs to the buffer is 30m via 4no 50mm underground pipes. My installer confirmed the system was running on the lastest firmware. Has anyone got any ideas please ?
could be to powerfull …
How is the" Compressorhyster.Heat." setting ? Default 7K, max, 15K
It may help to prevent the to early switch off and reduce cycling