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How Do I Know if My Furnace Control Board is Bad?

However, as the heart of your furnace, your control board could show signs of wear and tear in a number of ways — and with so many possible causes, furnace problems can be a tricky fix.

Look for the Signs

The good thing about your furnace is that it always finds a way to tell you there’s a problem. The confusing part is understanding what the signals mean. So, how can you tell if your furnace control board is bad? Here are some of the most common red flags to watch out for.

Warning Light Is On

The first place to start is the control board itself. Often, your control board contains warning lights to alert you to a problem within the system. The lights indicate a series of different diagnostic issues that can be explained with the help of your owners manual or by an HVAC technician. The diagnostic lights can be seen through a small clear viewing window located on the front door panels of your furnace. It is helpful to note and record the flash pattern of the lights. For example the flashes and a pause, three flashes and a pause, repeating. This will guide the diagnostics of the failure and reduce time on the repair.

Wavering Temperatures

Your life may be hectic, but your furnace is supposed to be stable. If you’re experiencing fluctuating temperatures in your home but your thermostat remains normal, that’s a sign there’s a problem with your furnace.

Event Sequencing

Chances are your thermostat functions as your mission control — and if you’re like most of us, the event sequence of your furnace can seem extraterrestrial. If you notice systems in your home functioning at unusual rates, such as the sounds of fans being cut short of its normal cycle, that’s an indicator of a control board issue in your home.

Next Steps

If you’re experiencing any of the issues seen above, it’s probably time to call in an HVAC specialist. While repairs and replacements may seem daunting, you’ll be prepared to go in and get the most out of your dollar (and your HVAC) once you learn how to spot issues.

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