Carrier gas heater
You may have a defective control board or blower motor. You will need to find on the main control board the location where the blower motor (marked heat) is connected. Using a volt meter, after resetting the limits and restarting unit, you will need to check and see if the board is supplying 1115 volts to blower motor (between the blower heat terminal and one of the neutral terminals on board). Also have someone hold in the door safety switch, or put a piece of tape on the switch, The switch will pop out when the bottom furnace door is removed, this is the normal location of control board. As the furnace goes through its normal cycle and prior to locking out on safety (limit opening) you should get 115 volts from the board (terminal marked blower / heat). If the board does not put out 115 volts, then the board is defective. If the board puts out 115 volts and the blower does not operate, the blower motor is probably defective, there is one more check to do. Close the door and put your system in cooling, see if the motor starts, if it does, then the low speed (reactor) is defective and motor needs replacing. If the motor does not start in cooling mode, you may have a defective capacitor. Check all of the above first and see what happens. Good luck, and be careful.
Dec 07, 2011 |