The central air conditioner is essential during the summer. The fan is an integral part of the unit as it distributes cool air throughout the room. If the air conditioner does not spin, the air circulation will be insufficient until you fix it.
The central air conditioner stops spinning due to faulty capacitors, contactor issues, faulty motors, broken fan belts, clogged filters, and other electrical problems. Check for common electrical problems, but most of the problems will need an expert HVAC’s help for troubleshooting.
There is nothing worse than your central air conditioner not spinning. A common issue is that the unit’s fan won’t spin while the unit runs. This guide will cover all the problems behind a central AC not spinning and how to troubleshoot them.
Signs your central air conditioner’s fan is faulty
Like other mechanical elements, the central air conditioner’s fan will damage due to constant wear and tear.
The fan is an important part of the fan that keeps running to circulate the air throughout the house.
If you pay a little attention to your unit, you will understand that the AC fan will break down soon.
Understanding these signs will give you time to prepare for the inevitable.
Weird noises from the unit
If the condenser unit releases a buzzing or rattling noise, it is because the motor blades are malfunctioning.
Turn off your unit to inspect the problem and avoid further damage.
The air conditioner suddenly stops spinning.
Sometimes, your unit will work fine but suddenly stop spinning.
Suspect overheating of the unit or the outside temperature is too hot for your central air conditioner to work.
The air conditioner does not produce cold airflow.
If the central air conditioner does not spin, it cannot distribute cold air properly throughout the house.
The chances are you have a dirty air filter. Change the filter to make your unit spin again.
The air conditioner’s fan rotation is slow.
When your central air conditioner spins slowly after rebooting, it will generate insufficient airflow.
It could be due to low fan speed.
Before troubleshooting it, check the fan settings in your thermostat.
The air conditioner is not spinning at all.
When your central air conditioner completely stops spinning, it implies a more serious issue.
There might be a possibility of malfunctioning internal components.
It would be best to hire an HVAC.
Another possibility is that the fan has reached its useful life cycle.
Why is the central air conditioner not spinning?
There could be numerous problems responsible for the central AC not spinning.
Some cases will need slight cleaning, while others require HVAC attention.
Let’s learn the reasons and how to solve them.
1. Damaged fan motor
The condenser fan motor is in the AC’s condensing unit.
If you find any vibrating noise from the condensing unit, the fan is out of balance.
But, if the fan does not spin, the fan motor has burnt out and requires a replacement.
The replacement cost will be around $300 to $1,000.
If the unit is small and old enough, consider buying a new one instead of replacing the fan motor.
2. Frozen evaporator coil
The evaporator coil takes out the heat and humidity from your house.
When the coil malfunctions, the coil will suck the cool air and freeze in the process.
As a result, the fan will stop spinning.
The freezing happens due to restricted airflow and low refrigerant.
So, you need to fix these two to fix the frozen evaporator.
Change the air filters every 3 to 4 months.
As for the low refrigerant, find the leakage source.
In most cases, cracked refrigerant lines are responsible.
Call an HVAC expert to replace the tube.
3. Faulty contactor
The contactor is a small device that controls the electricity flow on the air conditioners’ components.
The contactor also sends some voltage to kickstart the condenser unit and run the fan.
Over time, the contactor burns out due to constant wear and tear.
If the contactor is faulty, it won’t be able to send the voltage and run the air conditioner fan.
Contactors may be fine, but they remain stuck in the UP or DOWN positions.
If stuck in the UP position, the contactor will block the current flow between the components.
If the position is DOWN, the electricity flowing to the components will continue.
If the central air conditioner stops spinning, expect the contactor to be stuck in the UP position.
Hire a professional to correct the contactor position or replace it.
4. Dead capacitor
The capacitor sends power to the fans, like the contactor.
The capacitor’s fault is 30% when a central air conditioner does not spin.
The capacitor sends power to the fan motor and delivers energy continuously to keep it running.
If the capacitor is dead or broken, the air conditioner will not spin.
It may also make your unit blow warm air.
The central AC has two capacitors:
The start capacitor sends energy signals to the fan motor of the unit. When the motor receives the signal, it turns on the unit. If the capacitor is bad, there will be no signaling or spinning.
The run capacitor sends continuous signals to the fan motor to keep spinning. If the capacitor is dead, the fan motor will not be able to give the signal for spinning.
Some signs of a bad capacitor are:
- Air conditioner facing trouble in turning on.
- The unit is shutting off.
- The unit does not blow cold air.
- The unit makes a humming sound.
Try testing the capacitor with a screwdriver or small stick by sliding it between the vents and pushing the fan slightly.
The capacitor is bad if the air conditioner spins after the pushing.
To confirm which capacitor is bad, measure the power signal from the capacitor.
Use a watt meter and turn on the air conditioner.
When you turn on your air conditioner, you will see energy spikes from the start capacitor and wattage from the run capacitor.
If you don’t see any wattage or spikes, you have a bad capacitor for which the AC is not spinning.
Contact a professional to replace the capacitor.
5. Blocked air filter
The air filter traps the dirt particles from the outside air, which the air conditioner absorbs.
Over time, the filters will become dirty and restrict the airflow.
As a result, your central air conditioner will struggle to circulate the air if the clog is too much.
Besides, clogging can also shut down the entire system.
The easiest fix to this problem is to change the filters.
You can also clean it if the filter is washable.
To prevent the issue, change the filters every 3 to 4 months.
6. Broken belt
Most new central AC units do not count on the belt system but on direct motors.
If you have an older unit, the fan belt should work well.
If the belts break, they will stop your air conditioner from spinning.
Old belts are more prone to breaking, ripping, and fraying.
You can identify the problem when you hear a clicking, clanging, or squeaking noise.
A belt malfunctioning will lead to two scenarios:
- The fan belt has broken. So, the fan motor may work but cannot transfer mechanical work to the fan. As a result, the unit will not spin.
- The fan belt has slipped off the axis, and there will be less or no mechanical work to transfer to the air conditioner fan. In this case, the air conditioner will spin slowly or not spin at all.
If the belt has slipped, put it back on the axis yourself.
Consult an HVAC team to replace a broken belt. It would cost around $25 to $75.
7. Broken fan blades
Damaged fan blades will not let your central air conditioner spin properly.
The fan blades are visible through the outdoor unit’s vents.
If the blades are bent, cracked, or loose, they won’t spin.
Contact a professional to fix the blades.
8. Physical damages
There will be situations where the central air conditioner’s fans will receive physical damage and fail to function.
Before investigating the problem, turn off the thermostat.
Check for any physical damages and contact an HVAC professional to fix the damage.
9. Tripped breaker
Compared to all the damages discussed above, troubleshooting a tripped breaker is the easiest after the filters.
Suppose the circuit breaker connected to your central air conditioner is loaded with too many heavy appliances.
In that case, the breaker will trip due to an overloading breaker or an overheating unit.
Generally, one should load a circuit breaker with 80% of the current capacity.
If the load is more than that, the breaker will trip.
There is nothing to worry about here.
The tripping of the breaker is a precaution to prevent short circuits.
When the outside temperature is very high, for example, above 110°F, the wire resistance increases.
High resistance increases the amp absorption at the same voltage, therefore tripping the breaker.
When the breaker has tripped, you must unload the extra heavy appliances from the breaker or use one that can handle your air conditioner following the 80% rule.
Resetting the breaker will make your central air conditioner spin again.
Go to the breaker box, and check its position.
If the breaker is at the center, push it to the OFF position, wait for a few minutes, and then turn it to the ON position.
If the breaker is in the OFF position, flip it to the ON position.
Your central unit should start spinning after some time.
What should I do when the central air conditioner stops spinning?
If you are an inexperienced user, there is only a little for you to do except for calling the HVAC team for every little problem.
However, there are a few things that you can approach to at least inspect the problem.
Check the circuit breaker.
If you are fortunate, the problem could be as simple as a tripped breaker.
Check the breaker and reset it by flipping the switch.
If the breaker trips immediately after resetting, do not reset it again.
Instead, call a professional.
Clean the filter
Another easy solution is to check the filter condition and change it.
If the filter is reusable, wash it, dry it, and put it back.
While installing it, ensure the arrow directions remain the same as before.
Check the outdoor unit
The condensing unit can be the reason behind the air conditioner not spinning.
Examine unusual noises.
Check the vents and see if the fans are turning or not.
Check the thermostat
Check the thermostat’s configuration when your central air conditioner stops spinning.
There might be a possibility that the thermostat’s settings are set to HEATING instead of COOLING, for which the unit does not spin.
Change the setting to COOLING and AUTO.
The problem mostly happens with non-programmable thermostats.
If the central air conditioner does not spin, it cannot circulate enough air all over the house.
So, it is important to examine and troubleshoot when your air conditioner does not spin its fan blades.
Possible reasons include a damaged fan motor, frozen evaporator coil, faulty contactor, dead capacitor, broken blades, and damaged fan belt.
All these grounds will need professional attention.
Other issues like dirty air filters and tripped breakers do not require the HVAC’s help.
You can fix it by changing the filters and flipping the breaker switch.
Regular unit maintenance yearly will prevent these problems and encourage smooth functioning.
Can I run my air conditioner if the fan is not working?
You can run your central air conditioner if the fan does not spin. However, the unit will not work properly and won’t distribute any cold air to your house.
Why does my central air conditioner blow warm air?
Low refrigerant, dirty air filters and condenser units, faulty compressors, and leaky air ducts are common reasons behind the unit blowing warm air.