If your inside unit is running but the outside AC unit fan isn't running, there could be a few potential causes. To diagnose the problem, first, check the circuit breaker, then inspect the condensing unit for any visible damage, and then check if the fan's airflow is blocked.
When the outside unit breaks down but the inside unit is running, the culprit may well be a broken compressor in the outside unit. That's typically a major repair, something that might even warrant a system replacement.
This can happen if the system is set to "fan only," causing only the inside fan to circulate air without engaging the outside unit to cool the air. Other thermostat settings that can lead to similar problems include incorrect time or day settings, or an unresponsive touch screen.
Make sure the outside unit is turned on (there's probably a switch near the unit). If the outside unit has a separate circuit breaker, check your circuit box and make sure it hasn't been tripped. A more serious issue if the outside air conditioning unit's not working is a broken compressor, capacitor or fan.
The outside AC unit may not function effectively if one of the fans is compromised. You can identify if the blades in your AC unit are spinning by listening for a humming sound. Your AC condenser fan may not turn due to power issues, a burnt-out motor, a worn-out capacitor, or a faulty compressor contactor.
In AC systems, the air conditioner reset button is on the outside unit's lower edge, typically close to the ground. Some models have the reset button located behind the service panel, which may require tools to remove. Reset buttons are usually red or yellow with a clear “reset” label.
Does The AC Fan Outside Always Run? The answer to this is no. The AC fan does not run non-stop. It's intended to cycle on and off, depending on the needs of the HVAC unit.
Look for a Tripped Breaker
If your AC won't turn on, you can check two places for a circuit breaker or electrical panel. Older homes have a main electrical panel on the outside of the home or a circuit panel on newer homes. Check the electrical panel to see if the breaker is tripped. Reset it if it is.
A sure sign of a bad AC capacitor is a humming sound from within the access panel. Any humming noises indicate a problem with the air conditioning system or the components of the AC unit. Try turning the power on and off again to see if it was a one-time issue with the motor or a recurring problem.
Why Is My AC Fan Not Spinning? In short, common issues that can cause an air conditioning unit fan to stop spinning are electrical issues, problems with the capacitor, contactor issues, a burnt out air conditioner motor, a broken fan belt, or clogged air filter.
No Sound Coming From The Condenser
Listen if sounds are coming from your outdoor unit. It is a sign that it isn't working as it should if you don't hear any sound. Some air conditioners are designed to be quiet, but you should still hear a low hum.
A bad thermostat can be detected when your AC or furnace is not turning on, your HVAC systems are not turning off, the thermostat not responding, your HVAC system is short-cycling, the room temperature not matching the temperature displayed on the thermostat, and the programmed setting resetting themselves.
If you think your air conditioner has blown a fuse, the first sign you'll notice is that the outside AC unit is inoperable. The best way to check for a blown fuse is by using a voltmeter. Be warned — you are working with live electricity and should use extreme caution when troubleshooting your system.
Look for a RESET Button.
Some systems have a RESET switch on the outside unit. You can push this and see if it helps. If your unit does not, you can turn off the system at the thermostat, wait 5 minutes, and try again.
For AC capacitor replacement, anticipate spending between $150 and $400, depending on the capacitor's type and accessibility. A bad AC capacitor is a fairly minor repair, and most HVAC technicians will recommend a repair rather than replacing the unit when the capacitor is the problem.
It's a small, red button usually located on or around the unit. The button should have a clear 'reset' label. Once you find the button, press it for around three seconds and observe the AC. Check whether the AC kicks on immediately and if it doesn't, press the button again for another three seconds.
#1 Most Common Air Conditioning Repair – Bad Capacitor
The fan of course makes a whirring noise, the compressor is like a deep buzz like a refrigerator running. Holding your hand above the fan should feel warmer than the outside air.
If your HVAC capacitor is bad, the motor will run at higher amplification, run backwards or stop running altogether.
The outside unit may not run if it's shut off or the safety switch is engaged. Worn parts, like fan motors or contactors, can prevent the unit from turning on. Debris inside or outside of an AC unit can keep it from running properly. If a bad compressor is to blame, you'll need to install a new cooling system.
Generally, an AC capacitor will last around 20 years, but there are a number of factors that can shorten that lifespan. If you've noticed performance issues of any kind with your air conditioner, take the time to run your system through its phases and review its performance.
The main reasons your AC unit outside is not turning on could be something that has tripped the circuit breaker, something is blocking the fan's airflow, or the condensing unit is damaged. Other potential issues could be the thermostat isn't set correctly or the compressor could be malfunctioning.
A central AC system consists of indoor and outdoor units. An indoor air handler can continue running when the outside unit has shut down. While air will blow from the vents, it won't be cooled; it may be as warm as the summer air outside.
If the compressor is working, but the fan won't turn, then the problem is most likely with the motor and/or capacitor. When an AC fan is not spinning and no audible indications of compressor activity are detected, it is usually due to a lack of power or a malfunctioning compressor contactor.