IGH issue not yet solved.
After looking at different configurations of the IDR and IGH (orginal+Goldman's lab), it is clear that IGH circuits are fine. There is some IDR circuit which is triggering the He3 pump periodically.
This is detected by IDR at some point and it starts the SOS mode.
This is a default mode when the IDR starts up but couldn't get rid of once all valves are powered up.
The setup was stable yesterday after I kept the IDR in a test mode for several hours and then switching to remote+locked.
We will check if this helps to keep it stable.
He3 relay has been switched off. Need to rewire the relay box to start the He3 pump manually.