Peering through the window, you see snow flurries whipping through the air. You crank up the thermostat, waiting for the warmth to flood your living room as the furnace powers up. But as the minutes tick by, the heat fails to materialize. Could it be a broken blower motor? A busted heat exchanger? Understanding what parts break on a furnace, and how to spot the signs, can help you prevent a sudden lack of heat during the dead of winter.

1. Understanding Furnace Components: What Can Go Wrong

Understanding the various components of your furnace is crucial in identifying and fixing any issues that may arise. A furnace typically consists of a burner, heat exchanger, blower, air filter, thermostat, and various other parts that work together to provide warmth and comfort during cold weather. These parts can often fail or malfunction due to a combination of factors like wear and tear, poor maintenance, or age.

One of the most common culprits for furnace breakdown is a faulty igniter. This component allows the furnace to heat up and is typically made of fragile materials that can easily break. Another common issue is a dirty or clogged air filter, which can cause the furnace to work harder and overheat, resulting in damage to other parts like the heat exchanger.

The blower motor is another vital component of the furnace, and if it fails, the furnace may fail to produce enough heat or shut down entirely. The thermostat is responsible for communicating with the furnace to maintain a comfortable temperature, and if it malfunctions, the furnace may not turn on or off at the right times. Knowing these common problem areas can help you identify which part is causing an issue and take steps to repair or replace it.

2. Common Furnace Problems: Parts That are Prone to Breakdown

Understanding the common furnace problems and their components can help you identify the issues and get them fixed in time. Here are some of the most common furnace problems.

1. Air Filter

The air filter in your furnace is responsible for filtering out dirt, dust, and other particles from the air. It prevents the air ducts from getting clogged with debris, and also improves indoor air quality. Over time, the filter can become clogged and dirty, making it harder for the furnace to operate. This puts a strain on the blower motor, leading to higher energy bills and eventually, a breakdown. To avoid this, change the air filter every 1-3 months, depending on usage.

2. Blower Motor

The blower motor is responsible for circulating warm air throughout your home. It is one of the most critical components of your furnace system. Over time, the blower motor can wear out, leading to reduced airflow, strange noises, and increased energy bills. If you notice any of these signs, you may need to replace the blower motor or get it repaired by a professional.

3. Ignitor

The ignitor is responsible for lighting the gas burner in your furnace. If the ignitor fails to work, your furnace won’t be able to produce heat. The ignitor can wear out over time, or it may become dirty or damaged. Regular maintenance and cleaning can prolong the lifespan of your furnace’s ignitor.

4. Heat Exchanger

The heat exchanger is responsible for transferring heat from the burner to the air in your ducts. If the heat exchanger is cracked or damaged, it can leak carbon monoxide into your home, creating a dangerous situation. Signs of a damaged heat exchanger include strange smells, soot buildup, and a yellow burner flame. It’s important to get this part examined by a professional, as a faulty heat exchanger can also lead to increased energy bills and reduced comfort.

Identifying these common furnace problems and their components can help you prevent breakdowns and improve the lifespan of your furnace. Next, we’ll explore how to troubleshoot your furnace to find out which part is faulty.

3. Troubleshooting Your Furnace: How to Identify which Part is Faulty

If your furnace is not working properly, it could be due to a faulty part. But before you call a professional for help, you can troubleshoot and identify the faulty part yourself. Here’s how:

Step 1: Check the Air Filter

One of the most common reasons for furnace breakdowns is a clogged air filter. A dirty air filter can prevent air from circulating through the system, causing it to shut down. Check your air filter and replace it if it’s dirty. A clean air filter can improve airflow and prevent damage to other furnace components.

Step 2: Check the Thermostat

If the air filter is clean and your furnace still isn’t working, the thermostat could be the problem. First, check the battery level of your thermostat. If the battery is low, replace it and see if that solves the issue. If the battery is fine, check the settings and make sure they are set to the proper temperature. If the thermostat is not working properly, it could be due to a wiring issue, in which case, you will need to call a professional.

Step 3: Inspect Components

If the air filter and thermostat are not the cause of the problem, inspect the furnace components. Check the pilot light, the blower motor, and the gas valve. Look for any signs of damage, such as cracks, debris, or corrosion. If you notice any damage, call a professional to repair or replace the faulty component.

By following these steps, you can troubleshoot and identify the faulty part of your furnace. However, if you don’t feel comfortable making repairs yourself, it’s best to call a professional. They have the tools and expertise to diagnose and fix the problem quickly and safely.

4. Replacing Furnace Parts: Should You DIY or Call a Professional?

Replacing furnace parts can be both challenging and intimidating for homeowners who want to save money on repair costs. While it is possible to do some minor repairs yourself, it is important to know when it’s time to call in a professional. In this section, we’ll discuss the factors you need to consider when deciding whether to DIY or call a professional.

When to DIY

If you have some experience with DIY repairs and are confident in your abilities, certain furnace repairs may be possible to do yourself. Simple tasks such as replacing the air filter or cleaning the blower motor can be done with minimal difficulty. However, more complex repairs such as replacing the control board or blower motor require technical knowledge and specialized tools.

When to Call in a Professional

When it comes to complex furnace repairs, it’s always best to call in a professional. Attempting to repair a furnace without the proper knowledge and tools can lead to further damage, higher repair costs, or even safety hazards. Also, hiring a professional ensures that your furnace is properly fixed and ensures your safety.

Additionally, if you have a warranty on your furnace, attempting any DIY repairs may void the warranty. Always check the warranty information before attempting any repairs.

Comparing Costs

It’s essential to consider the cost of repairs when deciding whether to DIY or call in a professional. While DIY repairs may seem like a more cost-effective option, it’s important to remember that professionals have access to discounted parts, so the replacement parts can be cheaper when you hire a pro. Professionals also offer warranties on their work, which can provide you with peace of mind if something goes wrong.

In conclusion, while DIY furnace repairs can be economical, they can also be risky, particularly when complex repairs are required. When in doubt, it’s best to call a professional for your safety and the health of your furnace.

5. Extending The Life of Your Furnace: Maintenance Tips To Prevent Breakdowns

Regular Maintenance Is Key to a Long-Lasting Furnace

While it’s impossible to completely avoid all breakdowns, taking preventative measures can prolong the life of your furnace and prevent costly repairs. Here are some simple maintenance tips to keep your furnace in tip-top shape:

1. Change Your Air Filters Regularly: Clogged air filters can restrict air flow and force your furnace to work harder, leading to increased wear and tear on its components. Check your filter every 30 days and replace it as needed. A dirty filter may need to be replaced more frequently.

2. Keep the Area Around Your Furnace Clear: Make sure flammable materials, such as clothes, boxes, and other debris, are kept at least three feet away from your furnace. This helps prevent fire hazards and ensures that your furnace has proper ventilation.

3. Schedule Annual Professional Maintenance: Schedule an annual maintenance appointment with a professional technician. They’ll inspect your furnace for potential problems, clean the unit, and ensure it’s running efficiently. This can prevent small problems from turning into larger, more expensive issues.

4. Check Your Thermostat: Your thermostat controls your furnace’s cycles. Make sure it’s set to the right temperature and that it’s working correctly. A faulty thermostat can cause your furnace to run longer than necessary, leading to increased energy consumption.

By following these simple tips, you can help extend the life of your furnace and avoid costly breakdowns. Remember, a well-maintained furnace is a happy and healthy furnace.

6. When to Replace Your Furnace: Signs That It’s Time for a New Unit

Replacing a furnace can be an expensive and daunting task, but it becomes necessary when the furnace is no longer able to keep your home warm and safe. Here are some signs that indicate it’s time to replace your furnace.

Furnace Age

One of the most obvious signs is the age of your furnace. According to EnergyStar, the average lifespan of a furnace is around 15-20 years. If your furnace is more than 15 years old and has been experiencing frequent breakdowns, it might be more cost-effective to replace rather than repair it.

Increased Heating Bills

If your heating bills have significantly increased, this could also be a sign that your furnace is no longer functioning efficiently. As your furnace ages, it has to work harder to produce the same amount of heat, which leads to higher heating bills. If you observe an unexpected hike in your heating bills, it might be time to consider replacing the furnace.

Inconsistent Heating

If you notice that some rooms in your home are too hot while others are too cold, it’s an indication that your furnace is no longer working effectively. An older furnace often struggles to distribute the heat evenly throughout your home. It might be a good idea to get your furnace checked by a professional who can evaluate whether a replacement is necessary.

In conclusion, if you notice any of the above signs, consider replacing your furnace to avoid costly repairs and to ensure your family’s safety. Contact a trusted HVAC contractor to evaluate whether a new furnace installation is the right choice for your home. Remember to invest in regular maintenance of your furnace to ensure its longevity and avoid early replacements.

7. Conclusion: Keep Your Furnace Running Smoothly with Regular Maintenance and Professional Inspections

Regular maintenance and professional inspections are essential for keeping your furnace running smoothly. By keeping your furnace well-maintained, you can prevent breakdowns and extend its lifespan. Here are some tips to help you keep your furnace in good condition:

Schedule Regular Maintenance

It’s important to schedule regular maintenance for your furnace at least once a year. During a maintenance visit, a professional technician will inspect your furnace, clean it, and make any necessary repairs. This will help prevent breakdowns and keep your furnace running efficiently.

Change Your Furnace Filter Regularly

Changing your furnace filter regularly is one of the easiest and most important things you can do to keep your furnace in good condition. A dirty filter can cause your furnace to work harder than it needs to, increasing your energy bills and putting unnecessary strain on your furnace.

Keep Your Furnace Area Clear

Make sure the area around your furnace is clear of debris and flammable materials. This will reduce the risk of your furnace overheating, causing a fire, or circulating harmful gases like carbon monoxide in your home.

Know When to Call a Professional

While some minor furnace repairs can be done by a savvy homeowner, it’s important to know when it’s time to call a professional. Attempting to repair a complex issue yourself can be dangerous and may cause further damage to your furnace. If you’re unsure about how to diagnose or repair a problem, it’s best to call in a qualified technician.

In summary, regular maintenance and professional inspections are key to keeping your furnace running smoothly. By following the tips outlined above, you can extend the lifespan of your furnace while reducing the risk of breakdowns and other issues. So, make sure to do some research and find a reputable HVAC technician who can provide routine maintenance and repair services for your furnace.

People Also Ask

What are the common parts that break down in furnace?

The most common parts that break down in a furnace are the ignitor, flame sensor, limit switch, blower motor, and control board. These components can wear out over time due to normal usage, age, or lack of maintenance.

What causes a limit switch to fail in a furnace?

A limit switch can fail if it gets too hot, due to a lack of proper airflow or a malfunctioning blower motor. This can cause a safety shutdown and prevent the furnace from operating until the switch is replaced.

How do I know if my furnace ignitor is bad?

If the furnace is not producing heat, it may be due to a malfunctioning ignitor. This component can fail if it becomes dirty, worn, or cracked. Signs of a bad ignitor include a clicking or sparking sound when the furnace turns on, but no flame appears.

What are the signs of a bad blower motor in a furnace?

A faulty blower motor can cause a lack of airflow and heat in a furnace. Signs of a bad blower motor include unusual noises like squeaking or grinding, slow or weak airflow, or the motor not running at all.

How often should furnace parts be replaced?

Furnace parts like filters should be replaced every three months, while other parts like ignitors and flame sensors can last up to 10 years with proper maintenance. However, it’s recommended to have a professional inspect and service your furnace every year to ensure that all components are functioning properly.


A furnace has several parts that can break down over time, causing it to malfunction or stop working altogether. The most common parts that can fail include the ignitor, flame sensor, limit switch, blower motor, and control board. Regular maintenance and inspections can help prevent these issues and prolong the lifespan of your furnace.