Furnace Control Board Replacement, DIY And Save...
Our control board replacement guide will help you to diagnose and replace your furnace control. There are basically two types of gas furnace control boards.
The first type are simple ignition controls which control the gas valve, the ignitor (either a spark generator or hot surface ignitor), and a flame sensing circuit. These controls are more common on older less efficient units.
The other type is usually referred to as an integrated furnace control. These controls perform the same functions as the ignition control but also control the furnace blower in both the air conditioning and heating modes as well as providing onboard diagnostics.
**NOTE** ONLY YOU CAN ASSESS YOUR ABILITY TO PERFORM THIS TASK. THIS GUIDE CANNOT COVER EVERY POSSIBLE SITUATION.
The integrated furnace control is the heart of the furnace. Most of them have the same basic sequence of operations that they control. On a call for heat, they first start the induced draft motor (if the furnace has one). Then, the inducer causes a pressure switch to close. The control then either ignites the pilot, starts the direct spark ignitor, or starts the warmup of the hot surface ignitor.
After the pilot is lit and verified or the hot surface ignitor is warmed up (glowing bright yellow), the gas valve is energized. At the same time a timer begins to ensure that the burners were lit. In most cases a separate flame sensor proves that the burners are lit.
After the burners are lit, a timer starts and energizes the furnace blower after the set delay.
When the thermostat is satisfied, the control shuts off the gas. The inducer usually runs for about 30 seconds to purge the heat exchanger. A timer shuts the furnace fan off after a delay. This time delay is usually adjustable on the control board.
If the control does not cause the individual components to perform as described above, the control may be bad.
Most of the controls have built in diagnostic indicators. These are normally led lights that operate in flashes to indicate the problem. There should be a chart on the control or on the furnace access panel that explains the flashing codes. For many of the controls, there is a green light to let you know that the power is on and the control is functioning. If this light is not on, the control is usually reset by shutting the furnace power off for about 30 seconds and then turning it back on.
**HOT TIP** IF YOU HAVE TO RESET THE CONTROL, PERFORM MORE TROUBLESHOOTING TO FIND THE CAUSE. IT IS NOT NORMAL TO HAVE TO RESET THE CONTROL.
Once you have identified a defective control board, you continue your control board replacement by finding the proper replacement. This can be achieved by finding the manufacturer's part number or by using the furnace model and serial number. If you would like, we can find the proper replacement for you and you can purchase it through GOOGLE CHECKOUT. Simply click on the BUY NOW button where you can pay for your part then you can return here and submit the required information on the form below.
To begin the control board replacement, you should ensure that the power to the furnace is off. Then, you should mark all of the wires and write down which connections they go to on the board.
Then, you can remove the wires. The board may be held in place by screws or plastic clips. Remove the screws or clips and remove the old board.
Now, you can attach the new board with the screws or snap it in with the plastic clips. Carefully reconnect the wires you removed. VERIFY THAT THEY ARE ON THE PROPER TERMINALS AND THAT ALL WIRES ARE CONNECTED.
You should complete your control board replacement, by restoring the power to the furnace. Run the system through a heating cycle and verify proper operation.
You can get our Gas Furnace Troubleshooting and Repair DVD through GOOGLE CHECKOUT by clicking on the BUY NOW button. For $50 (which is less than the cost of one service call), you get our CONTROL BOARD REPLACEMENT video as seen here and also a complete set of videos grouped together on a single DVD. They will show you how to diagnose and repair the most common problems with high efficiency gas furnaces.