goodman furnace troubleshooting

Goodman, one of the most popular furnace manufacturers globally, is renowned for the reliability and efficiency that comes with its products. However, like all mechanical and electrical equipment, they may be faced with issues that would need specific troubleshooting and repair.

This article will guide you through common issues with Goodman furnaces, from troubleshooting error codes to understanding the step-by-step process of troubleshooting your house furnace in detail.

Exploring Common Challenges with Goodman Furnaces

Issues with furnace ignition are relatively common and can stem from various factors:

Degraded Ignitors: Over time, ignitors may wear out and fail to produce the necessary spark to ignite the gas. Visible signs of wear or damage are clues for replacement. Testing ignitors with a multimeter for continuity can confirm their functionality.

Gas Supply Problems: A consistent gas supply is crucial for furnace operation. If the furnace fails to ignite, check to ensure the gas valve is fully open. Inspecting the gas line for leaks is also vital; even minor leaks can disrupt furnace operation.

Flame Sensor Issues: The flame sensor’s role is to detect whether the burner has successfully ignited. Accumulation of dirt or a defect in the sensor can prevent it from detecting the flame, causing the furnace to shut off to prevent gas buildup. Cleaning the flame sensor with a fine abrasive pad or replacing it if defective can resolve this issue.

The gas pressure switch monitors the operation of the furnace to ensure it is running at safe pressure levels:

Clogged Tubing: The tubing that connects to the pressure switch can become blocked with debris or moisture, which may lead to inaccurate pressure readings. Regularly checking and clearing the tubing can prevent this problem.

Switch Malfunctions: A defective pressure switch may inaccurately read the pressure levels to be high or low gas pressure, which can cause the furnace to shut down unnecessarily. Testing the switch with a multimeter and replacing it if it fails diagnostics is recommended.

Overheating is a serious issue that can lead to gas furnace failure:

Blocked Air Filters: A common cause of overheating is a dirty or clogged air filter, which restricts airflow and causes the heat exchanger to retain too much heat. Changing the air filter regularly—every 1 to 3 months depending on usage—can prevent this problem.

Ventilation Obstructions: Ensure that all vents in the home are free from blockages. Closed or obstructed vents can cause similar issues as dirty air filters by restricting airflow and causing the furnace to overheat.

Thermostat issues can falsely indicate furnace malfunctions:

Improper Settings: It’s essential to ensure that the thermostat is set correctly to “heat” and that the temperature setting is appropriately higher than the current ambient room temperature.

Wiring Defects: Loose or corroded thermostat wires can interrupt the signal between the thermostat and the furnace. Check all connections for tightness and integrity. Replacing or repairing damaged wires can often resolve these issues.

If the furnace runs continuously or cycles too frequently, the cause might be more complex:

Thermostat Calibration: An improperly calibrated thermostat can lead to non-stop operation or frequent on-and-off cycling. Recalibrating the thermostat or replacing it if calibration isn’t possible can resolve this issue.

Faulty Limit Switch: The limit switch measures the internal temperature of the furnace. If faulty, it might cause the furnace to run continuously or not run long enough to adequately heat the home. Testing and replacing the limit switch if it fails can correct these operational issues.

Regular wear and tear can lead to various mechanical issues:

Blower Motor Wear: Bearings within the blower motor can wear out over time, potentially causing the motor to fail or operate loudly. Lubricating the bearings or replacing the motor can remedy this problem.

Old Belts and Pulleys: As the furnace ages, belts and pulleys can wear down, which might affect the operation of the blower system. Inspecting these components during regular maintenance and replacing them as needed ensures continued efficient operation.

Decoding Every Goodman Furnace Error Code

Goodman furnaces are designed with an advanced diagnostic system that utilizes specific error codes, conveyed through LED flashes on the control board, to assist both homeowners and technicians in swiftly pinpointing and addressing potential issues. Here’s a concise breakdown of common Goodman furnace diagnostic codes and their meanings:

  1. Steady LED Flash (Normal Operation): This indicates that the control board is receiving power and functioning as expected, establishing a baseline for diagnostics.
  2. Single LED Flash (System Lockout): This code often means the flame sensor is repeatedly failing to detect a flame, prompting the system to enter a lockout mode or start intermittently working. Repeated failures can be a sign to clean or realign the flame sensor.
  3. Two LED Flashes (Open Pressure Switch): This error manifests when the pressure switch does not close during startup, potentially caused by vent blockages, a faulty inducer motor, or a malfunctioning switch. Clearing any blockages or replacing defective parts is usually necessary.
  4. Three LED Flashes (Closed Pressure Switch): The opposite of the previous code, this occurs when the pressure switch fails to open after shutdown. Inspecting for constant operation or obstructions in the switch is advisable.
  5. Four LED Flashes (High Limit Device Open): Triggered by the high limit switch due to overheating, common causes include obstructed airflow, dirty filters, or a malfunctioning blower. Changing the filter and ensuring clear vents can often rectify this issue.
  6. Five LED Flashes (Flame Detected Without Gas): This unusual code suggests a flame was sensed even though the gas valve was closed, possibly indicating a leaky valve or a board issue. It’s prudent to check and replace these components as needed.
  7. Six LED Flashes (Lost Flame Signal): This appears when the furnace lights but then loses the flame signal. Causes might include a dirty flame sensor, poor grounding, or a faulty ignitor. Addressing these elements can often solve the problem.
  8. Seven LED Flashes (Limit Circuit Lockout): This indicates multiple failed attempts to operate, leading to a lockout. It’s usually triggered by safety switches activated to prevent overheating. Diagnosing the cause of overheating after resetting the furnace is essential.
  9. Eight LED Flashes (Gas Heating Lockout): A serious code indicating a failure in gas ignition leading to a non-auto-resetting lockout. Ensuring the gas supply is intact, the ignitor is operational, and all wiring is correct is crucial.
  10. Continuous or No Light:

    Continuous Light: This signifies that everything is running smoothly without any detected issues.

    No Light: Generally points to a power problem or a blown fuse. Checking power connections and the circuit breaker is recommended.

If these codes persist or the issue remains unresolved, seeking assistance from a qualified HVAC professional, such as those at Comfort Union is advisable. Their expertise will guarantee that any repairs are conducted safely and efficiently, helping to preserve the furnace’s optimal functioning and longevity.

Step-by-Step Guide to Diagnosing Goodman Furnace Issues

When encountering issues with your Goodman furnace, adopting a structured troubleshooting approach can help identify and potentially resolve problems efficiently, sometimes avoiding the need for costly repairs. Here’s how to methodically investigate and fix common Goodman furnace problems.


Ensure Power Supply: Begin by confirming that your furnace is properly powered. Verify that the circuit breaker is active and the furnace's switch is turned to the "ON" position. If the breaker has tripped, it may indicate an electrical trouble that requires attention.

Verify Thermostat Settings: An often overlooked factor is the thermostat. It should be set to “HEAT,” and the temperature should be set higher than the room's current temperature. Also, check the thermostat’s battery as low power might lead to inconsistent operation.

Airflow Restriction: A furnace forced to operate with a clogged filter may overheat or shut down due to restricted airflow. Examine the filter; if it is laden with dirt, replace it. Ideally, filters should be changed every one to three months, depending on environmental factors and usage.

Assess Ignitor: A non-heating furnace might have a defective ignitor. Observe if the ignitor glows upon startup. A non-glowing ignitor typically needs replacement.

Pilot Light and Gas Flow: For older models using a pilot light, ensure it’s lit. Follow the manual’s relighting instructions if it’s out. Also, check that the gas valve is fully open and supplying gas.

Clean the Flame Sensor: A furnace failing to fire up often has a dirty flame sensor. Remove and gently clean it using a soft abrasive pad, taking care not to damage it.

Burner Inspection: Dirty or misaligned burners can hinder the furnace's heating ability. Check for dirt or corrosion and clean accordingly. Ensure they are properly aligned for optimal function.

Examine Pressure Switch: This switch controls air pressure within the furnace for safe operation. If experiencing pressure-related errors, inspect the tubing for obstructions or leaks and clean if necessary.

Vent Assessment: Ensure vents are clear of obstructions like leaves, bird nests, or ice, which can cause airflow issues and affect furnace efficiency.

Inspect the Control Board: Look for any signs of damage or burning on the control board that might suggest electrical issues. Also, check for loose or corroded connections.

Testing Components: Conduct tests on components such as the blower motor or capacitor using a multimeter if you have the requisite electrical knowledge. Otherwise, consider professional assistance.

Persistent or Complex Problems: After attempting these troubleshooting steps, if your furnace still exhibits issues or you come across complex problems like continuous error codes or suspected gas leaks, professional expertise is recommended. Some repairs require specific tools and skills beyond the scope of DIY efforts.

Selecting the Right Professional for Significant Furnace Repairs

When encountering significant furnace issues that exceed the scope of basic fixes, it’s essential to seek out experienced HVAC professionals. Comfort Union is a reputable choice for those in need of specialized furnace repair services. Our service company is celebrated for its expert team of certified technicians who are adept at handling intricate furnace challenges.

Our Dedication to Customer Satisfaction

The dedication of Comfort Union to customer satisfaction and quality service makes them a standout option. Their skilled personnel are equipped to tackle a broad range of HVAC issues, ensuring optimal operation and safety of your system. Whether you require extensive repairs, maintenance, or an upgrade to a brand-new unit, Comfort Union tailors their services to meet your specific needs.

Moreover, Comfort Union understands the urgency that can accompany furnace malfunctions, especially during colder periods. They offer timely emergency repair services, which can be crucial when you need your heating system operational without delay.

You don’t need a second opinion with us. Opting for Comfort Union means securing top-notch customer service supported by advanced knowledge of HVAC systems and current best practices. Our technicians do more than just resolve immediate issues; they also offer advice on how to maintain your old or new furnace to prevent future problems, helping you maintain a comfortable and efficient home environment.

Contact us today for expert HVAC services or browse our website to learn more!

Frequently Asked Questions about Goodman Furnace Troubleshooting

Why is my Goodman furnace not coming on?

If your Goodman furnace fails to activate, first ensure your thermostat is correctly set to heat mode and the desired temperature is above the current room temperature. Check whether the circuit breaker has tripped or if the furnace switch is in the off position. Also, a dirty air filter can hinder operation, so replace it if needed.

How do you reset a Goodman furnace?

To reset your furnace:

  1. Power down the unit at your home’s electrical panel.

  2. Wait a moment to allow the system to clear out any stored errors.

  3. Restore power and observe if the system restarts without issues.

The reset button, typically found in the blower compartment, can also be used. It’s usually marked and may require you to open the furnace’s access panel.

Why won't my Goodman furnace stay lit?

A furnace that lights but doesn’t stay lit often points to issues with the flame sensor or pressure switch. A dirty flame sensor can be gently cleaned with a soft brush. If problems persist, the pressure switch and draft inducer motor should be replaced and be checked for functionality.

What does a blinking red light mean on a Goodman furnace?

A blinking red light on your furnace usually signals a specific fault. The number of flashes corresponds to an error code, which you can look up in your owner’s manual to identify the issue, whether it’s a faulty flame sensor, ignitor problems, or pressure switch issues.

Where is the reset button on my Goodman furnace?

The reset button on Goodman furnaces is often situated in the blower compartment. It’s usually clearly marked and may require panel removal for access.

How do you read a Goodman furnace code?

To interpret error codes from a Goodman furnace or test, watch the LED lights on the control board and count the flashes. Match this number with the error descriptions mentioned above to diagnose the problem.

How do you clear the fault code on a Goodman furnace?

Resetting your Goodman furnace by turning off the power at the breaker, waiting a few seconds, and powering back on can clear fault codes. However, if the underlying issue isn’t resolved, the codes will reappear.

What are common problems with Goodman air conditioners?

Issues with Goodman air conditioners often include leaking refrigerant, failed capacitors, unresponsive thermostats, and blocked condenser coils. Regular upkeep can help prevent these problems.

How do you reset a Goodman control board?

Reset the control unit and circuit board, by turning off the system at the breaker, waiting briefly, then powering it back on. This reset can resolve minor electronic glitches.

Other Furnace Troubleshooting We Offer

Share this: