If it doesn't do anything at all, the wires may be connected to the wrong terminals. I'm not positive, but I think if you have 3 wires, the Red/White goes to the +12 terminal, Black wire to the -12 Terminal, and Orange to the COMMS terminal.
Do you have a heat source in the basement? You may have had hot air rising behind the wall confusing the thermostat. If you get it running again, cycle it to OFF and press the + or - button to display the ambient temperature the thermostat is sensing. If it's reading a high ambient temp for some reason, it'll never turn the furnace on.