The Most Common Furnace Issues—and How to Fix Them

August 24, 2023

If it’s been a cold winter, your furnace has been running daily to keep you and your family warm and comfortable. If you’ve been diligent with maintenance, your furnace should be in good condition to keep up with the fickle Kansas weather. 

However, if you begin to spot furnace issues, it’s time to have your furnace inspected.

Given the humidity in the Midwest, keeping your furnace maintained is particularly important. Not keeping up with furnace maintenance could lead to costly issues that leave your home freezing on the coldest days—and our goal is to help you avoid that situation.

Here are the most common electrical furnace issues (along with six gas furnace issues)—and ways to address them:

Common Electrical Furnace Issues

1. Thermostat Malfunctions

Incorrect temperature readings or a malfunctioning thermostat can lead to inadequate heating. The thermostat is generally the first thing to check if your system is not heating or cooling. Regularly checking and calibrating the thermostat can help resolve this issue.

2. Ignition Problems

Electrical furnaces often rely on ignition systems or pilot lights to start heating. Malfunctions in these components can lead to intermittent or complete heating failures. Pilot lights can typically be reignited by following instructions on the furnace, while Ignition system issues call for a professional technician.

3. Faulty Heating Elements

Heating elements within the furnace can deteriorate or burn out over time, just like a lightbulb. This results in inadequate heat production and may require replacement by an HVAC professional.

4. Blower Motor Issues

The blower motor is responsible for distributing warm air throughout the space. Motor malfunctions can lead to uneven heating or a complete lack of airflow. You’ll need a professional to replace a blower motor on your system.

5. Electrical Connection Problems

Loose or damaged electrical connections can disrupt the flow of electricity, causing the furnace to malfunction or fail altogether. The experts at Hamilton can help!

6. Frequent Cycling

Short cycling, where the furnace turns on and off rapidly, can be caused by issues with the thermostat, airflow, or a malfunctioning heat exchanger. Identifying and addressing the root cause can prevent unnecessary wear on the system. In this case, you may need assistance from the professionals at Hamilton.

Common Gas Furnace Issues

1. Lack of Heat

If the system isn’t producing heat, there could be a few potential causes. Make sure the thermostat is set to heat, and move the dial up or down a few degrees to see if there’s a difference. 

Next, check to see if a circuit breaker or fuse has been tripped or blown. Go to the breaker panel and find the circuit that controls the furnace. See if it’s in the “off” position or if it’s in the middle. Flip it to the “on” position to reset it. If the furnace doesn’t start up, there could be wiring issues in the circuit or circuit breaker.

2. Problems with Burner Flames

Contaminated burners can lead to failures that affect the entire system. Inspect the burners for debris and remove it. The flames should be blue and even. Yellow flames indicate dirty burners that need to be cleaned. To clean the burners, turn off the power to the furnace and use a vacuum cleaner to remove debris from the burners and the area around the blower.

3. Rapid Cycling

A dirty or worn-out filter could cause a furnace to cycle on and off very quickly. If replacing the filter doesn’t address the issue, there may be a problem with the blower motor and belts. Pay particular attention to loud noises, or uncommon sounds as cycles start and stop. 

In this case, you’ll need to call an expert HVAC technical to like Hamilton Plumbing, Heating, A/C, Rooter for professional HVAC service

4. Lack of Air

If the furnace isn’t blowing any air, look into the inspection window to ensure the blower is clear of debris. Also, look to see if the light is flashing green. If it’s red, then you’ll need to call for service. If the light is off, the issue could be with the thermostat, run capacitor, blower motor, furnace control board, or transformer.

5. Continuously Running Furnace Blower

If the furnace blower doesn’t shut off, turn down the temperature on the furnace to see if this addresses the problem. Another potential cause could be an issue with the limit control switch.

6. Extinguished Pilot Light or Thermocouple Failures

The pilot light should always be on, as it is a small flame that ignites the burners. In gas-powered electrical furnaces, the thermocouple is critical for maintaining the pilot light. A malfunctioning thermocouple can lead to the pilot light going out, resulting in a loss of heat. If you suspect you have a faulty thermocouple, reach out to the technicians at Hamilton.

If you’ve followed the instructions in the owner's manual and the pilot light still doesn’t come on, reach out to Hamilton for quick and professional service.

4 Remedies for Furnace Issues

Furnace life expectancy is around 10 to 15 years for a well-maintained furnace. As a homeowner, you can perform simple tasks like changing filters, but we recommend calling an HVAC professional for maintenance assistance and comprehensive system checks. 

Some remedies can be done yourself, but when it comes to fixing common furnace issues, working with a trusted provider helps to guarantee that your heating system runs efficiently.

1. Recalibrating the Thermostat

The experts at Hamilton can recalibrate or replace your thermostat, ensuring your home’s temperature control is accurate. The cost varies depending on the type of thermostat.

2. Replacing the Filter

Homeowners can perform this task themselves, enhancing the furnace's efficiency and longevity. Filter replacement costs are relatively low, typically in the $10 to $30 range. Your HVAC professionals from Hamilton will also clean or replace filters during our visits for routine maintenance.

3. Resetting the Furnace

Our technicians are experts at diagnosing and repairing faulty components, with costs varying based on the specific issue. DIY attempts to reset the furnace can be made by following the manufacturer's instructions. Still, if the problem persists or you’re unsure about what you’re doing, we recommend calling Hamilton’s professionals for help.

4. Fixing Ignition Issues

The most common furnace problem often involves a malfunctioning or failed ignition system. Ignition issues can be caused by faulty components such as the igniter or thermocouple. An expert is needed to diagnose the problem and replace the defective parts.

What Is the Lifespan of a Furnace?

Furnace life expectancy is around 10 to 15 years for a well-maintained furnace. As a homeowner, you can perform simple tasks like changing filters, but you must call an HVAC professional for maintenance assistance and comprehensive system checks. 

Call Hamilton for Help with Your Furnace

Taking care of your furnace will help avoid costly repairs and ensure your furnace operates efficiently for years to come. While some issues can be addressed independently, it’s wise to call an expert at Hamilton to help with complex heating repair problems. 

Regular maintenance is an effective preventive measure that will help extend the life of your furnace, especially in the Kansas City area, where humidity makes it work harder. Invest in annual maintenance to avoid having a furnace malfunction during the coldest months. 

If you’re having furnace troubles or simply being proactive to avoid potential malfunctions, call your local HVAC professionals. The expert technicians at Hamilton can help with all your heating and air conditioning needs, including furnace installation. 

We want to help keep your home warm and cozy, even on the coldest days.