Air Conditioner Fan Running Too Slow—What Could Be Wrong?

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Experiencing a slow-running AC fan can be so irritating, especially on a hot summer day when the sun is in its full power and the temperature can be high. So if you're wondering why is this so, then you've come to the right place. We have researched and asked the experts about what could be wrong if this happens. And this is what we found out.

There are multiple possible reasons why your fan could be running slow. It is either the fan already needs cleaning as the dust has already build-up, or you have only chosen a lower fan setting. Some serious reasons like loose or damaged parts might need replacing. This is true, especially if you are using your AC daily. 

Are you still looking for more details regarding this topic? Continue reading as we discuss other related questions such as diagnosing your AC, how to increase fan speed, the cost of AC fan replacement, and many more. We will also be suggesting some awesome articles at the end of this write-up that will surely pique your interest. So go ahead and finish reading. 

Technician repairing the air conditioning unit, Air Conditioner Fan Running Too Slow—What Could Be Wrong?

Why Is My AC Fan Too Slow?

A slow AC fan can be because of two things, one is settings, which can easily be fixed by simply adjusting your fan speed to a higher level. The second one is because of mechanical problems in the fan itself. 

N0w obviously, the first one is a simpler problem compared to the second one, but let us dive in deeper and try to explain some possible reasons why our AC fans are not spewing enough air.

One of the simplest reasons why you can be experiencing slow fan speed is a dirty air conditioner. Now the frequency of having your AC cleaned can vary depending on your usage and location. If you live in a dusty or polluted area and frequently use your AC, it would be ideal to have its filter cleaned every month or two to make sure that it is not blocking the air that the fan produces.

Technician replacing the air conditioning filter

In this way, you can also check if other parts of your AC need some cleaning as well, including the AC fan itself. A dirty AC can cause it to underperform and also consume more electricity than it is intended to be. 

Mechanical issues such as a faulty run capacitor and fan bearings can cause the AC fan to struggle running and then cause weaker air production for the unit. This may result in the AC not being able to cool the room, or it may take longer for it to do so. 

Fan belt damage can also be a culprit in deterring the cooling performance of your AC. These belts are made out of rubber and over time can be stretched out and be due for replacement. 

These mechanical problems are more often than not caused by the wear and tear usage of the AC itself. If the AC is already old, it will naturally have some parts wearing out, especially the moving ones. That is why regular maintenance of your AC is important.

Not only will this help the performance of your AC but will also serve as a preventive check-up for parts that need to be replaced or repaired. This will also help in containing damages if any and help further the lifespan of your unit.

How Do You Know if Your AC Fan Motor is Bad?

Repairing the fan of the furnace

Now we have discussed some possible causes of a slow AC. Let us now discuss some indicators that if we notice are some telltale signs of a bad AC motor. If you are suspecting that your unit already has a bad AC motor, then this section can help you out. 

AC is Running Intermittently 

If you are experiencing sudden periods of automatic shutdown of the AC without you doing anything with it, then this is a sign that your AC motor is failing. An overheated motor can cause which can come from the issues with your relay motor.

No Cold Airflow

One very obvious sign that your AC fan motor is malfunctioning is the failure to produce cold air. The number one purpose of an AC unit is to regulate room temperature and most of the time it regulates it by making the room colder. This problem can come from a broken blower motor which is one of the parts responsible for spewing out cold air. 

Blades are Slowly Rotating

A damaged fan motor can also affect the rotation of the fan blades of your AC. Now, this depends on the design of your AC, if your AC has external fan blades that move automatically, you can observe them. If you notice that the blades are now rotating slower than they used to, it may come from a faulty motor. 

Irregular Noise Coming From the Unit

Noises like unusually loud rattling, buzzing, and humming can all indicate that there are malfunctions with your motor blades. These are more evident with older models as a result of wear and tear throughout the years.

Such noises are normal, especially if you do not have an inverter-type AC. But if those noises are more louder and irregular compared to normal, then you should immediately have it checked out. 

AC Fan Doesn’t Start

If in the first place your AC unit fails to start up, then you already have a broken motor. This can root from a lot of things but is usually caused by the age of the AC. Through time, these mechanical parts eventually run through their life expectancy. But it is true that some brands do last longer than others, so be careful when choosing an HVAC unit

AC Fan Doesn’t Stop

The opposite of a not starting fan is a fan that doesn't want to shut off. In some worse instances, you can have a combination of both. But when your AC starts to act up like this, it might be time for you to replace it.

If you are still not sure about what is wrong with your AC, consulting a professional AC technician is the way to go. This way you can have a proper diagnosis of what is truly wrong with your unit. Here you may also receive an expert's opinion if a repair will suffice or you totally need to buy a new unit. 

How Do I Increase the Fan Speed on my Air Conditioner?

Disassembling the air conditioning unit due to a system failure

Assuming that your AC is not broken, increasing your fan speed is relatively easy. Switching to a lower temperature means that the AC will be producing colder air, meaning that the lower the number indicated on the indicator of your AC or its remote control, the colder it will get.

If you are a bit confused about how to operate your unit, referring to the user's manual that came along with it is a great fix. The manual will have detailed instructions on how to understand and operate the unit. This will really help, especially if the AC unit that you have is advanced. 

Choosing the right AC is also very important. Your typical AC can be measured through horsepower (hp). The higher the horsepower your air conditioning has, the more powerful the motor it is equipped with.

This can also be one of the reasons why your AC unit is not able to cool the room and no matter how much you increase the fan speed of your AC, it still fails to do its job.

When choosing an AC unit, you have to consider the square footage of the room that you will be installing it in. You also have to take into consideration the number of things, especially electronics inside the room. This will have an impact on how much the AC unit will have to work to cool the room.

A bigger room with plenty of stuff in it will require a more powerful and high horsepower while small rooms like a one-person bedroom will usually be enough for lower horsepower ones to cool. 

That is why consulting with your local HVAC dealer before buying a specific unit is imperative, as you will be able to choose which AC is the right one for you. This will also help you save money in the long run as you will have a properly functioning HVAC. 

How Much Does it Cost to Replace a Fan Motor on an AC Unit?

Cooling coil and fan of a air conditioning unit

Now, this depends on the brand that you have, location (different places different rates), and whether or not some other parts need replacing as well. But you can expect to pay anywhere between the range of $300-$600. If you have a smaller unit, the price can be lower. Your motor's power can also dictate how much you will be paying. 

Motor repairs can be very expensive, that is why when they are broken, owners often opt to just buy a new one as repairs can cost nearly as much as a brand new unit. 

In Summary

Technician repairing the air conditioning unit

There are multiple reasons why your AC fan may be spewing out weaker air than what it usually does. A slow-running fan doesn't necessarily mean that there is damage to your AC but it is a possibility.

Regular maintenance is the best way to avoid encountering such problems. You also need to consider how old the AC unit is, this is because older ones are more susceptible to breaking down due to wear and tear over time.

Here are some related articles that we have previously written for you. Go ahead and check it out.

Goodman AC Fan Not Working – What To Do?

Should The Outside Cooling AC Fan Always Run?

Fan Only Mode Not Working On Furnace – What Could Be Wrong?

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