new honeywell rth6300b to replace very old honeywell thermostat
i have purchased a new honeywell thermostat (rth6300b) to replace an old honeywell thermostat. the only 2 wires from the old thermostat are RED and BLACK with no letter designation anywhere. i only have a heating system with no cooling, the heating system i have is a hot water system with radiators, a gas boiler with a pump. First of all, to help me better understand, what type of heating system do i have? where does the red and black wire go to on the new honeywell digital programmable thermostat? the possible slots on the new honeywell are as follows
G - W(O/B) - NOT USED - Y - R - Rc
I apprciate all your help!