M = Ø ¾” F SYSTEM FLOW
R = Ø ¾” M SYSTEM RETURN
C = Ø 14 mm DOMESTIC HOT WATER OUTLET (on prepared models only)
F = Ø 14 mm DOMESTIC COLD WATER INLET (on prepared models only)
S = Ø 100 mm M FLUE OUTLET
A = Ø 43 mm AIR SUCTION DEVICE
K = Ø ½” F SYSTEM LOAD WITH PLUG
X = Ø ½” F DRAIN SAFETY VALVE