Hi,
Currently I have a Honeywell analog(mercury) thermostat which I'm trying to replace with Honeywell RTH6300B. When I look at the current mercury stat wiring its lot different. I see a red wire connected to unmarked place. I see a yellow wire connected to something marked as "2" and a white wire connected to a dial marked as lounge and some numbers displayed across the dial.

Would l be able to use the RTH6300B with my current setup or do I need to get something else that will work with my current wiring setting? How do I connect my wiring to my new stat?

What type of system do you have? Gas furnace and A/C?
Typical wiring would be...
Red-24volts
White- Heat
Green- Fan
Yellow - A/C contactor

Have a honeywell thermostat. When set to the off setting the blower motor still comes on

Disconect the green wire from the thermostat and what happens?