just attempted to install honeywell 6300 thermostat. connected the G W Y R wires and left the blue alone. But now a 24 code is flashing on the furnace. And the thermostat isn't working. Any suggestions?
check the error code legends on the back of one of the doors. code 24 on a carrier may mean blown fuse on the circuit board and improper or shorted wiring. did you have a problem B4 changing the tstat?
"Cut it twice and it is still too short".