How To Adjust Blower Speed On Goodman Furnace

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Would you like to know how to adjust the blower speed on a Goodman Furnace? Well, we have researched this topic and have answers for you. It is helpful to understand how to change the blower speed on a Goodman furnace if you wish to save power or increase your furnace's blower speed.

To adjust the blower speed on a Goodman Furnace, you must access the control panel. On the control panel, there will be 16 dip switches in four switch banks, four switches per switch bank. Using the switch bank designated S5, adjust switches three and four to control blower speed. Here is the following pattern for all different blower speeds.

  1. Switch three off, and switch four off, which is 25% blower speed.
  2. Switch three on, and switch four off, which is 50% blower speed.
  3. Switch three off, and switch four on, which is 75% blower speed.
  4. Switch three on, and switch four on, which is 100% blower speed.

In this article, we will learn how to adjust the blower speed on a Goodman Furnace. We will also learn the answers to other interesting related questions like why CFM is important and can I put a bigger blower motor on my furnace. Keep reading to learn more.

A black colored Goodman furnace with wirings on the side, How To Adjust Blower Speed On Goodman Furnace

How To Adjust Blower Speed On Goodman Furnace

Sometimes you may want to adjust the blower speed on your furnace. Perhaps you would like to lower the speed to save on power, or maybe you would like to turn up the fan speed to maximum. Whatever the reason you would like to change your blower speed on your furnace, if you have a Goodman Furnace, you will be able to do just that.

To adjust the blower speed on your Goodman Furnace, the first thing you will need to do is access the control panel. A metal panel should slide off to expose the control panel.

Once you have access to the control panel, you will need to find the dip switches. They are typically located on the bottom of the control panel and should be arranged in four switch banks of four switches.

Each of these switch banks is labeled. The switch bank we need to adjust the blower speed is labeled S5. Now that we have found the S5 switch bank, we will need to adjust its switches.

There are four switches on the S5 switch bank, like the others. The only switches we will be concerned with are switches three and four.

Using a binary counting system, these two switches can be used to adjust the blower speed of your furnace to one of four settings. Each of the four settings increases the blower speed by 25%.

The Pattern

The pattern to adjust your blower speed is as follows.

  1. Switch three off, and switch four off, which is 25% blower speed.
  2. Switch three on, and switch four off, which is 50% blower speed.
  3. Switch three off, and switch four on, which is 75% blower speed.
  4. Switch three on, and switch four on, which is 100% blower speed.

Once you have selected the blower speed you desire, place the cover back over the control panel, and you are finished.

Now that we know how to adjust the blower speed on a Goodman Furnace let's find out if furnace fans have different speeds.

Do Furnace Fans Have Different Speeds?

Whether your furnace fan has different speeds will depend on what kind of furnace you have. Furnaces come with three different furnace fans types. The three main types of furnace fans are fixed-speed, multi-speed, and variable-speed.

While some of these furnace fans can be adjusted, others cannot. Let's take a closer look at these fans to see which have different speeds and which don't.

Fixed-Speed Furnace Fans

Fixed-speed furnace fans are designed to go only one speed. These fans operate at 100% power the entire time they are on. If you want to lower the speed on a Fixed-speed furnace fan, you have to turn it off. There is no other speed than on or off for these fans.

While these fans deliver excellent airflow, their inability to be lowered from full speed can make them loud. Also, since they always are on max power, they aren't very energy efficient.

This next furnace can be adjusted, and it is the Multi-speed furnace fan.

Multi-Speed Furnace Fans

Multi-speed furnace fans can be adjusted, and they often have two to four different fan speeds.

In some furnace systems, the fan speed is set to adjust automatically as needed, whereas, with other machines, you have to adjust switches on the control panel.

These furnace fans are great for selecting the right fan speed for the situation. If you are warming your house but getting too hot, you can lower the fan speed. If your AC is making you cold but, you want to keep the rest of your house cool, you can adjust for that.

While adjusting fan speeds is helpful, there is one drawback. With a multi-speed furnace fan, you must select one of several different fan speeds, and if the exact fan speed you desire is between two other fan speeds, there is no way to choose it.

That problem isn't an issue for our next fan. Now we will take a look at variable-speed furnace fans.

Variable-Speed Furnace Fans

Variable-speed furnace fans allow you to select an entire range of fan speeds. Like with multi-speed furnace fans, you can do this automatically or manually, depending on your specific model.

If you have to adjust your variable-speed furnace fan manually, then beside the control panel, there should be a pully. Pulling this rope can adjust the speed of your furnace fan.

If you have an automatic variable-speed furnace fan, you will not need to adjust anything. With the automatic, your furnace fan will always blow at just the perfect amount to save energy and keep your house at ideal temperatures.

Now that we know that some furnace fans have different speeds let's discuss what speed a furnace fan should run.

What Speed Should A Furnace Fan Run?

The exact speed your furnace fan should run will depend on the needs of your house. A big house will need a furnace fan running faster than a small house.

Most residential furnace fans run at about 1200 rpm with a max speed of around 1500 rpm.

The best speed for your house would be the slowest speed that still keeps the temperature where you want it. If your home can get away with half speed and still feel warm in the winter and cool in the summer, you should do so.

If your house is larger, you may need your furnace fan at 100% to keep things nice. Remember, the lower your furnace fan speed, the less energy it will cost to run. Keeping your furnace fan speed on the lowest speed that works for you should give you the best results.

Why is CFM important?

An air conditioning unit with blue ribbons attached at the grills

One of the most important things to consider when selecting a furnace is CFM. CFM stands for cubic feet per minute and measures how much air a furnace can push in a minute.

The higher the CFM, the more air your furnace can push. The reason this number is so significant is that if a CFM is lower than your house's needs, you won't be able to stay warm in the winter and cool in the summer. Your CFM should match your home.

You will not need a very high CFM if you have a small house. If your home is vast and spacious, you will need a furnace with a large CFM to keep the air nice.

With small houses around 900 square feet, you should look for a furnace with an output of at least 600 CFM. If you live in a sizeable 3000 square foot home, you should look for a furnace with around 2500 CFM.

Now that we know why CFM is so important let's learn how many CFM a Goodman Furnace has.

How Many CFM Is A Goodman Furnace?

The Goodman Furnace's most popular model has a CFM rating of 1200. This means that it can push 1200 cubic feet of air per minute. While this isn't the most powerful furnace on the market, it should work great for small to medium-sized homes. You can also adjust the blower speed down if you find that it pushes too much air.

While their most popular model has a CFM rating of 1200, there are other models of Goodman furnace that range between 600 and 2800 CFM. When choosing a furnace, remember to select the lowest-rated CFM that still works for your home.

Now that we know how many CFM a Goodman Furnace has let's learn if you can put a bigger blower motor in your furnace.

Can I Put A Bigger Blower Motor On My Furnace?

A furnace blower photographed up close

You can put a bigger blower motor on your furnace. Behind the control panel on a furnace is the blower motor. This part of a furnace blows the air through the house. If your furnace can't blow enough air, you may need to replace the blower motor with a bigger model.

We will now share how to put a bigger blower motor in your furnace.

How To Put A Bigger Blower Motor On My Furnace?

To put a bigger blower motor in your furnace, first, disconnect the wires to the control panel so you can slide it out of the way.

Behind the control panel will be the blower assembly. Remove the blower assembly by unscrewing all the screws holding it in place.

Once you have the blower assembly out of the furnace, remove the motor from the blower assembly. Once you have unscrewed and removed the motor from the blower assembly, replace it with a new, more powerful motor.

After your new motor is in place, begin reassembling the furnace by sliding the blower assembly back into place.

Once the blower assembly is in place, reattach the control panel and reconnect the wires as they were before. It may be helpful to write down where they connected or take a photo so you don't mess this part up.

Once the control panel is in place, slide the cover back onto the furnace, and your furnace will now have a more powerful motor.

To help with this process, here is a Youtube video on how to replace the blower motor on your furnace.

Final Thoughts

A black colored Goodman furnace with wirings on the side

This article taught us how to adjust the blower speed on a Goodman Furnace. We also learned how to put a bigger blower motor on your furnace.

We hope you enjoyed this article. If you want to learn more, check out some of these other posts.

Can A Heat Pump Replace A Furnace? [And How To]

Should Furnace Fan Be On Auto Or On (During Winter And Summer)

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