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How To Modify The Carrier Furnace’s Blower Speed

How To Modify The Carrier Furnace's Blower Speed

To get the correct temperature, your furnace’s blower speed needs to be changed. With a Carrier furnace, you can easily regulate the variable speed technology for constant comfort and energy savings. So, how do you alter the furnace’s blower speed? We have looked into the solutions for you.

By altering the pulley on the blower drive motor, you can alter the blower speed of a Carrier furnace. Turn the pulley clockwise after loosening the setscrew a little. Lowering the blower speed raises temperature while raising it at high blower speeds.

Always heed the warning about the risk of electrical operation when adjusting the blower speed taps. You run the risk of getting hurt if you ignore the warning.

Changing The Blower Speeds On A Carrier Furnace

How To Modify The Carrier Furnace's Blower Speed

Your Carrier furnace’s blower speed can be altered to control the temperature. If the machine’s temperature is within the acceptable range, consult the furnace rating plate. You can adjust the blower speed to fix the problem if the air temperature is outside the acceptable limit.

Increase the blower speed if you’re lowering the temperature. By reducing the blower speed, you can raise the temperature.

You must be familiar with the location of the blower motor before adjusting the blower settings. The motor is located on the furnace’s bottom cabinet. The blower door switch must be activated with 115V power in order to open the cabinet.

When you locate the motor, the selecting terminal will display 5-speed tapping. Different colors on the taps indicate different speeds. Before using the device, you can adjust the speed. Before changing the speed taps, turn off the power as a precaution.

According to the instructions, there are the colors of the 5-speed tap and the associated components it connects. With its factory-attached COOL, Gray has the fastest speed out of 5. Red’s fan, which is connected to the LO HT fan, has the lowest speed of 1.

The user’s manual also advises users to exercise caution to prevent unit damage. On all furnace models, you ought never to connect the RED and ORANGE speed taps to the HEAT factory while configuring the furnace.

The furnace will run outside the specified temperature range if the wires are connected to the heating element. The link harms the component as a result.

How The Blower Speed Can Be Changed

The steps of changing the furnace’s blower speed are as follows:

  1. On the blower drive motor’s pulley, make the necessary adjustments.
  2. The setscrew securing the pulley on the driveshaft must be loosened.
  3. When increasing the speed, rotate the pulley in a clockwise direction. If slowing down, turn in the opposite direction. Double-turn the pulley for a faster pace.
  4. Setscrew should be tightened after rotating.

When Should I Adjust The Furnace’s Blower Speed?

The blower speed can be changed for a variety of reasons. The most frequent causes are to alter the furnace’s noise level and warm airflow.

Increasing the speed to enable adequate airflow inside the furnace will assist. The increased airflow aids in drying out the air and eliminating register condensation issues. The enhanced speed, nevertheless, uses a lot of energy. Therefore, you must gradually raise your pace in order to conserve energy.

The blower speed can be lowered to make the furnace run more quietly and remove more moisture. It also reduces the furnace’s ability to use energy efficiently.

How Fast Should A Carrier Furnace Blower Motor Operate?

If using a 24-VAC motor, a Carrier furnace can run at varied speeds between 300 and 1300 RPM. Your home’s existing conditions will determine the speed you should set.

The air envelopes and insulation levels of contemporary dwellings with energy-efficient fixtures are tighter. Controlling the HVAC systems and adjusting them to the changing conditions becomes difficult as a result.

It is not, however, an easy task to complete. The types of heat in your home as well as the furnace itself must be taken into account. For the furnace to continue regulating humidity and comfort in the home, the components must function properly. 350 cubic feet per meter per ton is the furnace’s typical cooling airflow rate.

Because of this problem, the IECC has mandated mechanical sizing as a means of achieving energy efficiency. All of the new Carrier blower motors are ECM motors that are FER-compliant and have an electrical efficiency of between 80 and 85%.

In order to acquire the right blower speed setting, you should adjust the dip switches. The optimal setting is one that regulates humidity while maximizing the blower motor.

To make the changes, consult the product manual and seek for the cooling and heating air delivery table.

How To Fix A Carrier Furnace Blower Motor?

How To Modify The Carrier Furnace's Blower Speed

There are options accessible to you if the blower motor in your furnace causes issues for you.

To fix issues with the blower motor, follow the advice shown below:

1. No Power

Verify that the furnace is powered. A recent power outage, a tripped circuit breaker, or a blown safety switch fuse can all cause a power loss.

After a power interruption, you might try turning on the furnace to see whether the motor starts up again. Simply flip the breaker back to reset it if that was the root of the problem. Replace the blown fuse right away if that is the problem.

2. Too Low Thermostat Setting

The blower motor will not turn on if the thermostat is set to the lowest setting. The thermostat ought to be set at least three to five degrees higher than the ambient temperature.

In addition to the thermostat, make sure the fan is set to on so that it will also turn on.

Check to see if the thermostat is receiving power, just like the furnace.

3. Clean Vents And Filters In The Home

Keep the filters and house vents of the furnace clean to prevent the accumulation of dust and debris. The buildup of grime could get into the motor parts and stop the airflow.

Along with cleaning, the filters and vents need to point in the right direction to ensure proper airflow.

4. Check The Blower Motor

It’s time to examine the blower motor if the furnace’s component parts are in good condition. The furnace’s belt may be broken and needs to be replaced.

To check the belt issue, completely close the furnace door. Any belt that is ruined, frayed, or entirely worn out should be replaced. Make sure the replacement belt is positioned correctly before installing it.

Furthermore, the motor will overheat as a result of dirt, dust, and debris. These will clog the motor openings, speeding up the burning of the bearings and windings. If the blower motor and fan assembly still won’t move freely after additional examinations, apply a few drops of oil and see if the motor still operates.

If the old motor cannot spin freely because of damage, you need to replace it.

How Much Does A Carrier Furnace Motor Replacement Cost?

A new Carrier furnace blower will cost between $500 and $1,200, depending on the type. You can spend an additional $150 on labor if you let a technician repair the item. Verify that your product is still covered by the 10-year warranty to avoid paying any fees.

What Advantages Do Variable Speed Technologies Offer?

How To Modify The Carrier Furnace's Blower Speed

The best heating and cooling systems are now available thanks to technological innovation. The variable speed technology used by Carrier provides the following advantages:

  • Better Air Quality – Since the furnace is continually on, the air inside your home will be cleaner.
  • Consistent Comfort – When the air conditioner is running continuously, the temperature is nearly at the thermostat setting. There won’t be many hot or cold areas in your house as a result.
  • Improved Humidity Management – Because you won’t need to adjust the blower settings as frequently, the extended furnace operation will keep you comfortable.
  • Additional Energy Savings – Running the furnace constantly at lower speeds consumes less electricity.

With the aforementioned advantages, a Carrier furnace will make your home more pleasant for you.


A Carrier furnace’s blower speed can be altered by shifting the pulley and tightening the setscrews. Another method is to adjust the furnace’s speed taps to the appropriate speed.

When you need to raise or lower the air temperature and quiet the furnace, adjust the blower speed.

How To Modify The Carrier Furnace's Blower Speed

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