1 CAN SET THE SYSTEM PRESSURE TO 1-BAR AND THEN REMOVE THE FILLING LOOP. EVERYTHING WOKS OK WITH BOTH THE HEATING AND DOMESTIC HOT WATER. OVER THE NEXT 4 TO 6 HOURS THE SYSTEM PRESSURE WILL RISE TO ABOUT 3-BAR. I WILL THEN RELEASE WATER FROM THE SYSTEM UNTILL IT IS BACK TO 1-BAR AND THE PROCESS...