Altherma frequent compressor cycling

[Brian_UK]

Sadly no, I don't have a thermometer that is nearly precise enough to do such thing. Maybe I can get something in the afternoon, when I finish at work.

Good idea.

Although your flow indicators are working the measurement of the return loop temperatures would help you to balance the system better. You may actually have a short circuit through part of the system which will encourage early compressor shut down.

With the system running, work from the index fully open circuit and compare with the next circuit. Adjust flow valve to achieve the same, or closely similar, return temperature. Proceed through the whole system until all returns are at the same temperature.