Step 1
Locate the LED display panel for the furnace. This panel provides essential information. Once you locate it, ensure that the green light is on to indicate the board is functioning and the furnace has power. Alternatively, check to ensure that the furnace is plugged in if the green light is not on, or that a fuse is not blown in the main fuse box. A blown fuse will be in the off or neutral position in the box. In such a case, turn it back to the on position.
Step 2
Read the error codes on the LED display if it is flashing. The Goodman furnace is designed to lock out the initiating process if the circuit control board encounters an error at start-up. When that occurs, the LED display begins to flash a code.
Step 3
Count the number of flashes on the display. If the furnace senses more than one problem, it will flash a code first, and then pause before flashing a second code. The flashing will continue until you reset the display. Consult your owner’s manual for the note that corresponds to the flashing error code.
Step 4
Turn off the supply of power to the furnace if the circuit board is malfunctioning. It's likely the circuit board is malfunctioning if the board appears not to have power even if the fuses and power supply are fine. The circuit board is typically located inside the unit’s blower compartment.
Step 5
Inspect the circuit board thoroughly for a blown fuse. Look through the top of the fuse to determine whether it is blown. If you notice that the wires are disconnected, you need to replace the blown fuse. Ensure that no wires touch the circuit board frame if the fuse is blown. Replace any damaged or loose wires to keep the new fuse from blowing.