When removing and tagging the wires from the box to the old Thermostat, the two Neutral (White) were wired together with a wire nut, and a single White wire (pigged-tailed) was going into the Thermostat. One Black (Gray) into LOAD and One Black (Gray) into LINE were connected into the old thermostat.
The New Thermostat is a Honeywell CT410B that has 4 wires - L1 (Black/LINE)to connect Power Source/Breaker Circuit. Then L2 (Red/LINE) to connect Power Source/Breaker, The T1 (Black/LOAD), and T2 (Red/LINE) to connect to Radiator.
Question? Do I separate the two White to connect to new Thermostat (L2) separate (T2),
OR, Where can I connect the connected single White to what connection on the new Thermostat?