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What Causes Furnace Circuit Boards to Fail?

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what causes furnace circuit board to fail

Is your furnace experiencing issues with powering on or consistent cycling? Call professionals from Casper Friendly Systems to evaluate your furnace circuit board and restore your system.

New Jersey winters bring freezing temperatures that will force you to bundle up every time you leave your home. When you return, though, you’ll want warm, toasty interiors to keep you comfortable and avoid needing to bundle up indoors.

Furnace circuit board failure can allow the winter weather to seep into your property and cause discomfort. In this blog, we’ll teach you what causes a furnace circuit board to fail, so you can avoid shutdowns and stay warm throughout the winter.

If your furnace circuit board fails, call a trusted HVAC company in Jackson, NJ, to perform repairs and replacements. Top-rated furnace experts from Casper Friendly Services use the best tools and techniques to maintain your system. Call today to schedule services with our HVAC professionals.

What Is a Furnace Circuit Board?

Regardless of your furnace’s fuel source, the circuit board powers the system according to your thermostat settings. Think of the furnace circuit board as the “brains” of your furnace. Functions like ignition, gas valve operation, flame sensor, heat exchanger, and blower motor operation would be impossible without this essential piece.

Keeping your furnace circuit board functional also impacts other parts of your HVAC system. In fact, most systems only operate on one circuit board that controls both the furnace and air conditioner. As a result, circuit board problems for your furnace will cause issues for your air conditioning, too.

Common Reasons for Circuit Board Failure in Furnaces

Knowing what causes a furnace circuit board to fail allows you to prevent or troubleshoot the problem before calling professionals for repairs. These 10 common furnace issues can leave your circuit board in disrepair and your home susceptible to winter weather.

Power Surge Damage

Power surges happen for many reasons. Most of the time, a power surge occurs when too many people simultaneously operate electrical devices in your home. However, thunderstorms and power line damage also cause power surges.

When your home experiences a power surge, it can cause electrical damage to any connected device. As such, these events could damage the furnace circuit board, causing system failure.

Clogged Air Filters

Your HVAC air filters cleanse your interior air and prevent health issues from dust, debris, and bacteria. However, constant furnace use will eventually lead to clogged filters. Dirty and clogged filters can cause various furnace system malfunctions, including circuit board failure.

When your air filters are too dirty to enable proper airflow, dust and debris can float back into the system. These contaminants can cause overheating or a fuse fire that could destroy your circuit board. Replace your filters monthly to avoid circuit board failure.

Stuck Relay Switches

Furnace relay switches direct the power in your system. Over time, these switches can become dirty and get stuck in the open position.

As a result, power could be flowing improperly in your system and overcharge the furnace circuit board. Routine maintenance can help avoid relay switch warping and misalignment that leads to these issues.

Improperly Sized Fuses

Your home’s fuses provide a safety barrier against power surges. When a surge floods your electrical framework, fuses automatically shut down the system and prevent damage.

However, fuses that are too small to handle your unit’s capacity won’t properly protect your system from surge damage. You may have improperly sized fuses if you operate on an older system, allow unqualified technicians to perform installation, or install your own system.

Transistor Failure

The transistor on your furnace circuit board operates as the electrical regulator. As the gate and amplifier for all electricity to your board, it maintains a steady flow of power and prevents electrical issues.

Power surges, aging, and other damage can cause your transistor to fail. When this occurs, your circuit board won’t operate either. The transistor is typically the first part to fail on a circuit board.

Loose Wires

Furnaces vibrate when they operate. These vibrations can eventually loosen the wiring on the furnace circuit board, leading to failure. Fortunately, tightening electrical connections and wiring can quickly restore the functionality of these pieces.

Failed Starting Capacitor

The starting capacitor for your furnace provides the first jolt of electricity needed to get the blower motor running. Over time, your starting capacitor could wear down and eventually fail altogether.

While your circuit board could be in perfect condition, a failed starting capacitor could make it seem like your board is not working. Calling experts for inspections and repairs is the only way to identify whether a failed circuit board or starting capacitor is causing the issue.

Dysfunctional Blower Motor

Blower motor problems can impact your entire system. Failing blower motors may overwork to compensate for developing damage, straining the electrical load of your system.

As your system tries to compensate, the increased electrical burden could lead to shorting or a blown fuse. These issues can cause your furnace circuit board to fail as well.

Dirty Sensors and Fuses

Like your air filters, the mechanical components of your furnace require routine cleaning. Dirty flame sensors and fuses can lead to ignition issues, electrical shorting, and overworking the unit. If you haven’t called professionals for furnace cleaning in many months, your dirty system could lead to a failed furnace circuit board. 

Aged or Expired Unit

Ultimately, an aged or expired system could cause furnace circuit board failure. After about a decade of operation, you will likely start noticing system decline and increased maintenance issues.

While repairs could keep your system functional for another couple of years, the increasing costs of maintenance work may not be worth it. Furthermore, a failed circuit board will require replacement anyway, making a system replacement the best option for aged units.

Diagnosing Furnace Circuit Board Failure Causes

When your furnace circuit board fails, it will shut down your system. Although you’ll know you have a problem on your hands, it may be difficult to detect what causes a furnace circuit board to fail.

The best way to diagnose the cause of furnace circuit board failure is by calling professionals for system inspection. While certain clues might indicate potential causes, experts have the tools and experience to examine your system, identify the root of the problem, and devise a repair plan.

Circuit Board Troubleshooting Tips

Although you’ll likely need to call professionals for inspections and maintenance, there are some troubleshooting tips you can try first to restore your system. Some furnace circuit board troubleshooting tips include:

  • Replace air filters
  • Restart your system
  • Open your vents and ensure that no objects are blocking them
  • Check that your thermostat setting reads “heat”
  • Check the pilot light
  • Check your breakers

Seasonal Circuit Board Failure Risks

While furnace circuit boards can fail at any time of year, different seasons can increase or decrease the likelihood of these issues. It’s most common to experience furnace control board failure during the winter. These months require higher level operation from your system, causing more strain and a higher potential for system failure.

Summertime circuit board failure is more rare since you won’t be operating your furnace during these months. However, leaks and additional moisture from increased humidity could cause problems even without the circuit board running.

Circuit Board Replacement vs. Repairs

When your circuit board fails, you might want HVAC professionals to repair the issues immediately. However, most circuit board repairs are far too expensive to justify.

In most cases, a circuit board replacement will be more cost-effective and reasonable than repairs. However, if other components of your system (i.e., the starting capacitor) cause the problem, repairs may work.

Proper Furnace Maintenance Practices

Hiring HVAC professionals for routine maintenance, usually twice a year, offers the best prevention strategy for circuit board failure. Maintenance experts from Casper Friendly Services perform comprehensive maintenance practices, including:

  • Tightening electrical connections
  • Replacing air filters
  • Testing and recalibrating thermostat settings
  • Checking all mechanical and electrical components
  • Cleaning sensors, fuses, and ductwork

Will a Warranty Cover the Replacement Cost?

Most homeowners won’t want to pay full price for their furnace circuit board replacement. Fortunately, a parts warranty for HVAC equipment could alleviate replacement costs. Check your warranty to see if you qualify for this assistance.

Call Top-Rated Furnace Technicians from Casper Friendly Services

When your heating and cooling systems experience issues, you might not know what questions to ask an HVAC technician during the repair process. At Casper Friendly Services, our knowledgeable professionals bring a wealth of HVAC knowledge to every repair job. With the tools and techniques to efficiently repair furnaces and boilers, your home will never suffer discomfort from the winter weather.

We guide you through the entire repair process to keep you informed on everything going on with your system. Our diverse financing options ensure that every person can obtain high-quality HVAC services to maintain their home comfort.

Are you still unsure what causes a furnace circuit board to fail? Call 732-656-8258 to resolve your furnace electrical issues with top-rated HVAC professionals from Casper Friendly Services.

Author Bio:
Matt Casper

The Business Owner of Casper friendly services features a team of trusted HVAC contractors in Neptune, NJ. Local trustworthy business owner with 9 years experience! Honest, professional, and most of all affordable. Call Casper today to discuss your HVAC needs!