Few things are worse than sitting in your home, shivering as the temperature drops. When your furnace blows cold air instead of warm, it’s time to take action by adjusting the blower speed. The blower is responsible for distributing warm air throughout your home, so it’s essential to make sure it’s functioning correctly. In this article, we’ll walk you through the steps on how to adjust blower speed on your furnace and keep your home at a comfortable temperature all winter long.

1. Understanding Blower Speed: A Guide to Your Furnace’s Settings

Blower speed is an integral part of your furnace’s settings. It’s responsible for distributing the warm air throughout your home. Changing the blower speed can have a significant impact on the furnace’s efficiency and performance. In this section, we’ll discuss the basics of furnace blower speed and its significance in the heating cycle.

What is Blower Speed?

Blower speed refers to the rate at which the air is pushed out from the furnace into the duct system. The blower motor controls the speed of the blower and uses different speeds depending on the temperature requirements and other settings of the furnace. There are typically three blower speed settings: low, medium, and high.

Why is Blower Speed Important?

Blower speed is a critical factor that affects your furnace’s energy efficiency and overall performance. The speed setting determines how much warm air is distributed around your home, the noise level of the furnace, and indoor air quality. It’s important to choose the correct speed based on the heating requirements and the size of your home.

A lower blower speed results in a warmer air temperature and higher humidity levels. This setting is ideal for cold weather conditions and helps to maintain a comfortable temperature throughout the home gradually. A higher blower speed distributes a greater volume of air at a faster rate, which is suitable for milder weather conditions. It’s important to note that higher blower speed settings can consume more energy and increase utility bills.

The Different Types of Blower Motors

There are generally two types of blower motors found in furnaces: single-speed and variable-speed motors. Single-speed motors operate at a fixed speed and are designed for use in furnaces with a traditional heating system. They are less energy-efficient and are more likely to cause temperature variations in the home.

On the other hand, variable-speed motors are designed to operate at different speeds depending on the furnace’s heating requirements. They are more energy-efficient, quieter, and help maintain a consistent temperature in the home. They also provide better indoor air quality by ensuring that the air is effectively circulated throughout the home.

Understanding the blower speed setting is crucial to optimizing the performance of your furnace. It can help you control heating costs and improve indoor comfort in your home. In the following sections, we’ll discuss how to adjust and troubleshoot blower speed issues to ensure optimal furnace performance.

2. Step-By-Step: How to Adjust Blower Speed on Your Furnace

Adjusting the blower speed on your furnace can help you fine-tune its performance and maximize efficiency. Here is a step-by-step guide to help you adjust the blower speed of your furnace.

Step 1: Locate the Blower Motor

The blower motor is typically located in the air handler or furnace cabinet, and it is responsible for powering the fan that circulates the air in your home. Locate the motor and identify the speed control switch or dial.

Step 2: Turn Off the Power

Before adjusting the blower speed, turn off the power to your furnace by switching off the circuit breaker or removing the fuse. This will prevent any accidents or injuries during the adjustment process.

Step 3: Determine Current Speed Setting

Check the current speed setting of your blower motor by looking at the switch or dial. Most furnaces come with three-speed settings – low, medium, and high. This will help you determine how much you need to adjust the speed setting.

Step 4: Adjust the Speed Setting

Use a screwdriver to adjust the speed setting switch or dial of your blower motor. For example, if your current setting is medium and you want to increase the speed to high, turn the switch or dial to the high setting.

Step 5: Turn On the Power and Test

After making the necessary adjustments, turn on the power to your furnace and test the new speed setting. Listen for any unusual sounds or vibrations, and check the air flow from the vents to ensure that it is at the desired level.

Remember that adjusting the blower speed can affect the performance and efficiency of your furnace, so it is important to consider the factors mentioned in the previous section. If you are unsure about making any modifications to your furnace, it is best to seek expert assistance.

3. Factors to Consider Before Changing Furnace Blower Settings

Before you start adjusting the blower speed on your furnace, there are some important factors that you need to consider. These factors will ensure that you are making the right changes to your furnace’s settings and that you are not causing any damage to the system.

1. Furnace manufacturer instructions: Before you start any work on your furnace blower speed, it is important to read the manufacturer’s instructions thoroughly. These instructions will give you important information on how to adjust the blower speed and any other specific instructions for your furnace model.

2. Furnace age: The age of your furnace can also play a role in adjusting the blower speed. Older furnaces may require a gentler touch when making any changes to the settings, as they can be more fragile and delicate.

3. Type of furnace: Different types of furnaces require different blower settings. For example, gas furnaces typically require a higher blower speed than electric furnaces. Make sure you are familiar with your type of furnace and its specific requirements before making any adjustments.

4. Ductwork and filters: The condition of your ductwork and filters can also affect the blower speed settings. If your filters are clogged or your ductwork is blocked, it can put additional strain on the blower motor. Make sure to check these areas before making any changes to the blower speed.

By considering these factors before making any changes to your furnace’s blower speed, you can ensure that you are making the right adjustments for your specific furnace. This will help to maintain the efficiency and longevity of your system.

4. Troubleshooting Common Issues When Adjusting Furnace Blower Speed

Adjusting blower speed on your furnace is a crucial aspect of keeping the temperature in your home consistent and comfortable. However, it’s important to be aware of some of the common issues you may face while adjusting the blower speed on your furnace. Here are some tips on how to troubleshoot these issues:

No Change in Blower Speed

If you’ve adjusted the blower speed on your furnace and the speed does not seem to be changing, there may be an issue with the control board. In this case, you should check the control board for any loose wires or damaged parts. If you’re not comfortable inspecting the control board, it’s best to leave it to a professional.

Noisy Blower Motor

If your blower motor is making unusual noises after adjusting the blower speed, this may be a sign of a damaged or worn-out belt. It’s best to replace the belt as soon as possible to prevent any further damage to the system.

Inconsistent Blower Speed

If you notice that the blower speed is inconsistent even after adjusting it, this may be due to a dirty air filter or incorrect blower wheel size. Check to see if the air filter needs to be cleaned or replaced, and ensure that the blower wheel size is correct for your furnace model.

By troubleshooting these common issues, you can ensure that the blower speed on your furnace is functioning properly and efficiently. If you’re unable to identify the issue or unsure about how to fix it, it’s always best to contact a professional for assistance.

5. Importance of Proper Blower Speed: How It Affects Your Furnace’s Efficiency

One of the crucial components of a furnace is the blower motor, which helps to circulate air throughout your home. The blower speed is an essential factor that determines how efficiently your furnace operates. A proper blower speed is necessary for various reasons, including:

  • Efficient heat distribution: Your furnace’s blower motor is responsible for moving heated air throughout your home. A proper blower speed ensures that your furnace distributes heat evenly, providing comfortable temperatures throughout your home.
  • Optimized energy consumption: A blower motor running at the correct speed consumes optimum energy, which means you won’t be spending more on energy bills than required. A blower motor operating at an incorrect speed can consume more energy than needed, leading to higher energy bills.
  • Improved lifespan of your furnace: An improperly adjusted blower speed can lead to increased wear and tear on your furnace, leading to more frequent repairs and reduced lifespan of your furnace.

Adjusting The Blower Speed: A Key to Efficient Furnace Operation

You may want to adjust your furnace’s blower speed to suit your heating needs, but before doing so, it’s essential to understand how it works and what impact it can have on your furnace’s efficiency. Adjusting the blower speed is best left to a professional technician who can balance the setting where it won’t put undue stress on your furnace’s components and lower its efficiency.

A technician often factors in various factors, including the size of your home, ductwork, furnace capacity, and many more, before adjusting your furnace’s blower speed. A properly adjusted blower speed can keep your furnace running efficiently and extend its lifespan by reducing wear and tear and preventing costly repairs.

6. Using Advanced Tools: Maximizing Your Furnace’s Blower Performance

If you want to optimize your furnace’s blower performance and increase its energy efficiency, using advanced tools may be necessary. Below are some tools that can help you achieve maximum blower performance:

Digital Manometer

A digital manometer is a tool that measures the pressure within your furnace’s ductwork. By using this tool, you can determine whether the airflow is within the range required by your furnace manufacturer and make adjustments accordingly.


An anemometer measures the velocity of air during your furnace’s operation. It can help you determine whether the airflow is adequate to meet your home’s heating needs and identify any insufficiencies. You can use this tool to investigate whether there are any clogs or obstructions within the ductwork that are impeding airflow.

Duct Calculator

A duct calculator is a tool that can help you calculate the required air volume for your furnace. By entering data such as the furnace’s output capacity and duct material, the duct calculator will determine the appropriate duct size for your furnace and help you identify and correct any duct design issues.

Using advanced tools to maximize your furnace’s blower performance can effectively increase the efficiency of your system and cut down on energy costs. The data obtained from these tools can help you make informed decisions about your HVAC system’s maintenance requirements and avoid any potential problems. If you are not comfortable using these tools yourself, consider hiring a professional HVAC technician to perform an assessment on your system.

7. Professional Help: Knowing When to Seek Expert Assistance for Furnace Maintenance


Explanatory Sentence: While adjusting your furnace blower speed can be a simple task, there may be times when expert assistance is required for furnace maintenance.

When to Seek Professional Help

If you have followed all the steps to adjust your blower speed but still experiencing issues, it is time to call in an expert. Your furnace is a complex system consisting of many components, and a malfunction in one area can significantly impact its performance. A professional technician can accurately diagnose the issue and provide the necessary solutions.

Another reason to seek professional help is when you have limited knowledge in HVAC systems. DIY may seem like a cost-efficient way of handling your furnace maintenance, but it comes with a risk of causing further damage, resulting in costly repairs. A licensed professional has the education, experience, and tools required to handle your furnace safely and efficiently without causing more harm.

It is always advisable to have your furnace inspected and maintained annually by a professional technician to avoid costly repairs and ensure safe operation. These inspections can help technicians identify and fix small problems before escalating into more significant issues. Additionally, an annual inspection can ensure that your furnace remains up to code and runs efficiently, reducing energy costs.


While adjusting blower speed is a simple task, it can sometimes be a daunting one. Seeking a professional’s help can be an added advantage. A reputable HVAC company can provide the necessary solutions ranging from maintenance, repairs to replacement, ensuring your furnace runs efficiently while keeping your living space comfortable.

People Also Ask

1. Why should I adjust the blower speed on my furnace?

Adjusting the blower speed on your furnace can help improve the efficiency and effectiveness of your heating system. It can also help reduce energy consumption and lower your heating costs.

2. How do I know if I need to adjust the blower speed on my furnace?

You may need to adjust the blower speed on your furnace if you notice that the airflow in your home is too weak or too strong, or if you are experiencing uneven heating in different areas of your home.

3. Can I adjust the blower speed on my furnace myself?

While it is possible to adjust the blower speed on your furnace yourself, it is recommended that you have a professional HVAC technician handle this task. They have the knowledge and expertise to ensure that the adjustment is made correctly and safely.

4. What tools do I need to adjust the blower speed on my furnace?

The tools you will need to adjust the blower speed on your furnace will vary depending on your specific make and model. In general, you may need a screwdriver, pliers, and a voltmeter to make the necessary adjustments.

5. How much does it cost to adjust the blower speed on my furnace?

The cost of adjusting the blower speed on your furnace will depend on a number of factors, including the make and model of your furnace, the extent of the adjustments needed, and the rates charged by your HVAC technician.


Adjusting the blower speed on your furnace can help improve the efficiency and effectiveness of your heating system. While it is possible to make these adjustments yourself, it is recommended that you have a professional HVAC technician handle this task to ensure that it is done correctly and safely. By making the necessary adjustments, you can enjoy improved heating performance, reduced energy consumption, and lower heating costs.