The control board in your furnace is responsible for starting a heating cycle and shutting it down. Power from the furnace switch goes to the control board and the control board distributes the power where it's needed to make your furnace work in the proper sequence.
If the control board is faulty, your furnace may not turn on or it may turn on and not shut off. A heating repair technician has to test different parts to narrow down the problem to the control board. If the board is bad, it has to be replaced. Here's an overview of this heating repair.
How To Tell If The Furnace Control Board Is Bad
The heating repair technician may start with the likely reasons your furnace isn't starting up first. They may check the circuit breaker, fuse in the furnace, and thermostat for malfunctions. Next, they may trace the thermostat wiring that goes to the control board to see if it's loose or damaged.
When the cover is off the furnace, the repair technician should be able to see the control board easily. The board has a number of wires attached to it, including the main wire from the power switch. If all the wires are attached securely, the repair technician can check the power going into the board with a multimeter and then check the power coming out. If power goes in but doesn't come out, the board is bad and has to be replaced. The technician may even tell the board is bad if it has a hot spot from a component overheating.
How To Replace A Bad Furnace Control Board
The heating repair technician has to turn the power off to the furnace first since the board is connected to a high-voltage wire. Most of the other wires are low-voltage that go to the various parts of the furnace. There are so many wires connected to the control board that it's easy to get them mixed up when putting the wires on the new board.
A way to deal with this problem is to leave the wires attached and unscrew the board from the furnace panel so it can be removed. Then the new control board can be secured to the panel with screws. After that, the heating repair technician can take one wire off of the old board at a time and place it into the matching slot on the new control board. When all the wires are hooked back up, the repair technician can restore the power to the furnace and check to see if the thermostat can get the furnace to turn on and off as it should.
For more information on heating repair, contact a professional near you.
