A control board failure is a major furnace problem. It may require replacing the appliance, depending on the unit’s age and the severity of damage. The things to do when your heater won’t turn on won’t help if the furnace control board has gone bad. If it’s not fixed, the entire system can malfunction.
When you have a faulty control board, performance issues, particularly with the fans and burners, can occur. We’ll look at what this component does and when it’s time to repair it or schedule a furnace replacement.
Understanding Your Furnace’s Control Board
The control board is an electronic circuit board located inside your furnace. There are two common types; these include a simple ignition furnace control board, which is found in older models and controls the igniter, flame sensor, and gas valve (it’s installed alongside the fan control board). It’s less expensive and easier to install than an integrated control board, which, integrates fan and ignition control in modern furnaces and works more efficiently.
Where the Control Board Is Located
The control board is located inside the furnace’s control panel. You can find it behind the front panel at the bottom of the appliance (check the manual for its precise location). It looks like a circuit board with several relays and resistors attached.
Why the Furnace Control Board Is Important
The control board is attached to the ignitor, motor, gas valve, and other components by wires. It controls the temperature of burners, the speed of the fan motor, and when the fan should turn off or the gas should turn on. Aside from communicating with the thermostat, the board receives data from various sensors to monitor temperature, gas pressure, airflow, and other parameters.
Signs of a Faulty Furnace Control Board
The reasons for a control board malfunction include power surges, extreme cold, and wear and tear. Improper installation can also lead to a circuit board failure in your furnace. There are many signs that the control board has gone bad, including the following:
- The Furnace Isn’t Turning On: Your furnace can stop working due to a tripped breaker, incorrect thermostat setting, and other reasons. If you can’t find an obvious cause, the control board may be malfunctioning.
- Your Home Is Too Hot or Too Cold: If the furnace is not responding to the thermostat, some rooms or your entire home may be uncomfortable. A circuit board malfunction may be causing components to turn off too early or stay on too long.
- Erratic Furnace Behavior: Your heating system should run in a regular sequence of events. If the blower stage suddenly stops, the gas jets don’t turn on, the ignition is delayed, or the blower continues running after the unit has shut off, the issue may be with the control board.
- The Furnace Is Short Cycling: Intermittent furnace operation is a sign the circuit board isn’t receiving or sending the right signals. Call a technician if the issue isn’t caused by a clogged filter or other obvious issue.
- The Blower Motor Is Running Constantly: A faulty control board can cause the blower fan to keep running even after the heat is turned off.
- Error Codes on the Furnace Display: Most furnaces have LED diagnostic indicators that blink in codes to represent specific problems. Check the manufacturer’s instructions for a guide on what each pattern means. A diagnostic light may be located on the board itself.
Troubleshooting Control Board Problems
A blinking indicator light on the board means an issue has been detected. While a chart in the manual can help determine what component is affected, further testing may be needed. A technician can perform voltage testing for the board’s power supply, its output power, or the thermostat terminals. Unless you have experience with this, hire a licensed HVAC professional to troubleshoot the issue.
When to Consider Furnace Replacement
The furnace control board can last from five to 15 years, which means it can last the entire life of your heating unit. Too much dust and debris or extreme temperatures can shorten the component’s life and can increase wear on your furnace. If a control board failure happens near the end of your heater’s expected lifespan, it’s more practical and cost-effective to replace the furnace.
Age is one reason to consider furnace replacement. Other reasons to start planning on a heating system upgrade include:
- Loud noise while the furnace is running.
- Temperatures are constantly fluctuating.
- Your energy bills keep increasing.
- Soot is building up near the furnace register.
- The burner flame is yellow.
- Your furnace has had multiple repairs in the past year.
Benefits of a New Furnace
Aside from dealing with another control board malfunction or other furnace problem, replacing your old furnace can have the following benefits:
- Increased Energy Efficiency: Your old furnace has likely been declining in efficiency for a while. A new model works more efficiently. Plus, modern furnaces are engineered to save energy. For maximum savings, look for Energy Star-rated models.
- Improved Heating Performance: New furnaces have technological advancements including variable-speed blowers that adjust output to match your heating needs. Multi-stage heating allows for more precise temperature control. Most models are also compatible with smart thermostats that can adapt to your heating schedule and be controlled remotely.
- Better Indoor Air Quality: In addition to more reliable and efficient heating, modern furnaces use advanced filtration systems to more effectively remove dust, dander, pollen, and airborne particles in general. Newer filtration technology can provide relief from allergies and asthma during every season.
- Long-Term Savings: Despite the initial investment in furnace replacement, a new unit can save you in the long run. New furnaces require fewer repairs and are less maintenance intensive, so operating costs are generally lower, especially if you purchase an Energy Star-rated system. Plus, there are tax credits, rebates, and other financial incentives available.
- Increased Property Value: If your heating system is up-to-date, your home may be more appealing to potential buyers. Energy efficiency is an attractive selling point. A potential buyer also doesn’t have to worry about replacing their heating system anytime soon.
How to Find a Qualified HVAC Technician
To find a qualified and reputable heating repair contractor, search for reviews of HVAC companies in your area. You can also narrow down your search to contractors with experience handling furnace control board failures. Check their websites to learn about their specialties, licensing, and years in business. If you’re not finding enough options, ask family members, friends, or neighbors for referrals and contact each company to learn more about it and request an in-home consultation.
FAQs
How Do I Know If Something Other Than the Control Board Is Causing the Problem?
A faulty control board can cause various issues. The code on the indicator light can tell you what’s wrong. A licensed HVAC technician has the tools and equipment to further diagnose the problem.
Can I Replace a Furnace Control Board as a DIY Project?
Unless you’re qualified to repair furnaces, you should hire a trained professional. The job entails working with internal components. Therefore, a mistake can cause serious damage and safety issues, while attempting DIY work risks voiding the warranty.
What Happens If I Ignore a Faulty Control Board?
Ignoring the problem will only lead to more heating issues. Aside from your home becoming increasingly uncomfortable, safety hazards are possible as are additional furnace malfunctions. Eventually, your heating system may shut down.
Contact Express Plumbing Heating & Air Today
A control board failure is a serious problem our technicians can address quickly. They know everything there is to know about gas furnace repair and installing a high-efficiency replacement furnace. In business since 2006, we’ve become the #1 heating contractor in Boise thanks to our NATE-certified contractors and dedicated management team. Our solutions are tailored to ensure your comfort and help you save.
To schedule heating, AC, or plumbing service or learn about financing and our protection plans, call (208) 502-4718 today.
