The control board of your air conditioner, also called a printed circuit board, is the command center of your air conditioner. It is responsible for sending signals to the indoor and outdoor units based off the commands inputted in the thermostat. When the circuit board becomes faulty, a replacement is needed to operate the AC unit using its thermostat or remote control.

Diagnosing Faulty AC Circuit Board

#1 Input Commands and Output Action are Different

If you notice that your air conditioner operates with settings different from what you input through your thermostat or remote control, then there may be a problem with your circuit board. You can check this by comparing the settings on the LCD of your control board with the settings on the LCD of your indoor unit.

If the settings are mismatched, then the indoor unit may have gotten the wrong commands from the control board, or is not getting any commands at all. Replacing the control board should fix the issue.

#2 Inconsistent Temperature

Circuit boards send commands to HVAC systems, notifying of the preferred temperature and fan settings input through the thermostat. Malfunctioning circuit boards may sometimes cause HVAC systems to fluctuate in temperature due to short circuits, dust, or faulty signals. This can happen to a furnace control board as well, as it commands the heat pump.

#3 Air Conditioner is Malfunctioning

If your air conditioner is malfunctioning, such as when you cannot power on the HVAC system, switch fan modes, or change the temperature, then the problem is most likely due to a faulty control board. Most air conditioners have a remote control, which makes it convenient for users to adjust settings. However, a faulty control board will cause the unit to malfunction.

How to Replace AC Control Board: A Step-by-step Guide

It is not recommended to repair HVAC controllers yourself as this requires the skills of a licensed technician to do. It can be costly as well, and you're better off getting an entirely new control board replacement, or having the HVAC controller repaired at an AC service company like Luce Aircon.

Step 1: Cut the Power

First, cut the power to your air conditioning unit. You will be opening up, and dismantling your HVAC system, and blocking the power source of your system will prevent any accidents and mishaps.

Step 2: Open the Housing

Next, open the housing of your unit. Unscrew the bolts keeping everything in place, and remove the panels. You can do this using a screwdriver, or a power drill. Make sure to keep track of all the parts so you can put them back together later on.

Step 3: Dismantle the Air Conditioner

Dismantle the air conditioner piece by piece until you get to the control board. Remove the air filter, set aside the coils and fins, and other components that are in the way. Some air conditioners have the circuit board visible and unobstructed, so check for the control board first.

Step 4: Locate the Control Board

Locate the control board. This is often positioned right by the blower fan, just behind the bottom access panel. Check the control board, and take a photo of its wiring connections to use as a reference later on.

Step 5: Disconnect the Wiring

Carefully disconnect the wiring of the old circuit board. Make sure you have the wires properly labeled to make it easier for you to connect the new board properly. Unscrew the control board, and set it aside.

Step 6: Place the New Board In

Carefully secure the new part in place, and use the reference photo you took earlier to connect the wires back together. You may need to solder the connections to secure them. Close up the air conditioner, and restore the power to your unit. Test out your repair to see if it was done correctly.

AC Circuit Board Replacement Cost

The cost to replace a circuit board may range between $130 to $650, depending on the requirements and specifications of your circuit board. Having a professional HVAC technician handle the repairs will optimize your repair costs as labor and replacement parts are often packaged together for a better price.

Where to Buy Replacement Circuit Boards

While there are multiple shops that sell circuit boards, not all circuit boards are suitable for use in air handler units. Skip the stress of having to figure out what replacement part you need, and have our technicians handle the repairs.

Our team at Luce Aircon can find the exact item you need to finish the repair, and can do the repairs for you as well. Circuit boards are especially tricky to repair, but our technicians have decades of experience repairing air conditioners across all brands and models.

‍

Check out our full list of services, and give us a call to schedule your next appointment!