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There are several reasons that can cause the blower fan of your air conditioning unit to malfunction. These can include a lack of electrical power, damaged components, worn-out parts, or even the accumulation of dirt and dust.
A blower fan is among the most vital components of any air conditioning system.
It is responsible for ensuring proper air circulation and helps the system function at optimal levels. However, like any other part, it can break down and cause problems. In such situations, the first step to resolving the problem is to find out why the fan has stopped working.
And this guide will help you do just that. So, let’s begin!
Reasons Why Your Fan Blower Is Not Working
Here are some of the most common reasons that can stop your blower fan from working:
1. Lack Of Power
Your blower fan might not be working due to lack of power to the air conditioning unit. To fix this, check that the circuit breaker or power switch is turned on. The circuit breaker may be located on the main panel, the unit itself, or a nearby wall.
In case the switch is turned on, check for a blown fuse or a disconnected or loose wire. Alternatively, an electrical connector might have become corroded and may be responsible for the issue.
2. Blocked Air Filter
If you cannot feel any warm air coming out of the air conditioning unit, its filter may have become clogged with dust. A dirty air filter can prevent the blower fan from functioning effectively and in such cases, it is important to clean the filter of the unit to solve the issue.
3. Frozen Evaporator Coils
A frozen evaporator coil or refrigerant lines may be another reason your blower fan is not working. To check this, turn the unit on, switch to the air conditioning mode, and look for ice near the indoor unit, which may be blocking the passage of air. Until the ice melts, air will not be able to pass through the coils, so you should turn off the air conditioning immediately.
4. Flooded Overflow Pan
Your HVAC system may have a sensor switch that can detect water in the drain tray. When that happens, the air handler will prevent the heat pumps or the air conditioning from starting to prevent leaks into the ceiling or the building insulation.
5. Worn Out Or Loose Fan Belt
In the case of a belt-driven blower motor, the belt may be damaged or may have gotten loose. This will result in the fan motor running, but the fan will not work. Fortunately, a loose belt can be tightened using the screws located on the sides of the motor. On the other hand, if the belt is worn out, it will need to be replaced.
6. Bad Relay
In an AC system using a control board or relay, it is the relay that powers the blower fan. And a faulty relay or a bad control board can also stop the fan from working. While a faulty relay can be replaced using DIY methods, getting a professional to do that is recommended for the best results.
7. Malfunctioning Pulley
A malfunctioning pulley may be another reason why your blower fan is not working. This generally happens in the case of a belt-driven assembly. In such cases, the blower motor will be operational, but the fan will not function.
8. Faulty Capacitor
The capacitor is that part of any appliance responsible for storing electrical power and supplying it to the circuit board when the appliance is switched on. In case of a bad capacitor, or one that has shorted out or become weak, it will not be able to supply enough energy for the fan motor to run.
9. Bad Fan Motor
As with other parts, the fan motor can go bad over a period of time, or its bearings may seize up. In either case, the result will be a non-working blower fan. Depending on the cause and level of damage, the fan motor will need to be repaired or replaced completely.
10. Damaged Bearings Or Blower Assembly Shaft
If the bearings of the assembly shaft have seized up, it can cause the fan motor to draw a large amount of power. But due to the stuck bearings, the fan blades will not turn. It is easy to detect damaged bearings because the HVAC system will start making squeaking noises in such cases.
11. Malfunctioning Fan Limit Control Switch
In a furnace heating system, the fan limit switch controls the on and off functions of the furnace blower assembly. In other words, it is the part that determines when hot air is required. If the switch starts malfunctioning, the blower fan may not turn on.
12. Overheating Motor
If the heat pump system is able to turn on but cannot function properly, it may indicate that the blower motor cannot distribute hot air effectively due to overheating. The most common reason for a motor overheating is dust accumulation, so check the filters and clean them properly. Again, this will prevent the fan from working properly.
Blower Fan Not Working Frequently Asked Questions ?
How Does An HVAC Fan Work?
The furnace blower motor is responsible for sending warm air from the air conditioner, heat pump, or heat furnace to your home. The system heats or cools the air as needed, and the blower motor sends it through the duct system and out from the vents.
What Are The Different Types Of Blower Fans In HVAC Systems?
Blower fans can be differentiated into two categories, depending on their motors. The first kind is single-speed motor fans, which, as the name indicates, operate at a single speed. And the other type of blower fans are variable speed ones, with high-velocity motors that can adjust their speed to produce different airflow levels.
What Can Cause Your Fan To Blow Hot Air?
“Why is my fan blowing hot air?” is a common question among people who rely on fans more than HVAC systems. Unlike air conditioning systems, a fan does not cool the air but simply circulates it, promoting better sweat evaporation. However, you may feel it is blowing hot air if there is no proper ventilation or the heat is too extreme for sweat to evaporate quickly.
How To Know That Your Blower Motor Is Failing?
Certain signs indicate that your blower motor is failing and can help you fix the problem well in time. The first of these is low airflow from the vents, which can mean that the motor has started to wear out or may already be broken.
Another sign that may indicate a problem is when the fan operates only at specific speeds. Generally, in the case of variable speed fans, the speed can be controlled by the user. But if you are unable to change the fan speed, there may be a problem with the motor.
Finally, no air may be coming out from the vents when the unit is turned on, which may indicate that the blower motor has short-circuited or failed completely. Usually, in such cases, the blower motor cannot be repaired and requires a replacement.
What Are The Best Fans For Cold Air?
If you’re wondering what fan blows the coldest air, there are lots of options on the market. However, it ultimately comes down to personal preferences, though certain factors can help select the right option. For instance, it is better to go with a blower fan with variable speeds than a single-speed one.
These generally offer greater customizability and are more powerful than single-speed ones.
Blower Fan Not Working Final Thoughts
Proper care and maintenance are necessary to ensure that your blower fan performs well for a long period. However, even with that, situations can arise when it might need repairs or replacements.
And when it comes to that, it is best to rely on professional repair services rather than performing the repairs yourself. This is because they have the required tools and experience required to perform such repairs, ensuring that they are performed efficiently.
On that note, it is time for us to conclude this guide. Until next time!
