I just replaced my thermostat and wired it the same as the last. The furance fires up and the fan turns on but the blower motor doesn't turn on. Any suggestions?

Furnaces usually have their own blower control in heating (the thermostat does not activate the blower in heating mode.) Did the blower work before changing out the thermostat or will the blower run if you turn the fan switch to on at the thermostat? A make and model of the furnace will help if you can give it.

The blower did work before I changed out the thermostat. When I turn the fan switch to on, the fan does run. I have a gas furnace and it is a Carrier Weathermaker 8000VS.

Sounds like your blower really on the control board went bad.

Is it bad to still be running the furnace until I have someone come over to fix it?

Nope just leave your fan on the on position. And set the heat where ever you want. You can check the conecton in the furnace to see if it is loose or come off before you call someone out, a control board is fairly expencive.

Have you re-tried the old thermostat, or tried jumping the "R" and "W" circuits directly together? What type of thermostat did you install? If by chance it has an anticipator that is adjustable AND it is set to a value that is too low, the thermostat may be terminating the demand for heating before the unit has run long enough for the blower to turn on.