Why is my AC unit not kicking on the outside?

Author: Lloyd Lindgren  |  Last update: Sunday, May 24, 2026

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.

Why is my AC unit not turning on outside?

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.

How to get outside AC unit to kick on?

Outside AC Unit Won't Turn On? What to Do Before Calling for Repairs
  1. Make sure the thermostat is set to COOL. ...
  2. Check the emergency or shut-off switch. ...
  3. Check the inside unit's power switch. ...
  4. Look for a blown fuse or tripped circuit breaker. ...
  5. Look for problems with your condensate drain line. ...
  6. Try resetting the air conditioner.

Why is my outside unit not running but inside is?

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.

Why is the outdoor of an AC unit not working?

If your outside AC unit is not turning on, it could be a thermostat issue. If your thermostat clicks but the AC does not turn on, you could have an issue with the thermostat itself. Broken thermostats often fail to properly communicate with the rest of your heating and cooling system.

Outdoor AC Unit Not Running, Not Turning On! Top 10 Problems!

Why is my AC running in the house but not outside?

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.

How do I reset my outside AC unit?

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.

Why is my condenser not kicking on?

A condenser that won't come on could have a variety of problems, because there are many issues that would prevent activation. The wiring might be wrong, a motor might be faulty, the compressor could have gone bad, or it is completely out of refrigerant. Might even be a problem with the thermostat.

How do I force my AC unit to turn on?

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.

Why is the outside fan not working?

Let's start with the obvious – if your outdoor fan isn't getting ANY power at all, well…it's not going to spin! A tripped circuit breaker or blown fuse cutting electricity could easily be why that fan motor hasn't engaged. Loose or corroded wiring connections to the unit are another power problem to investigate.

What would cause my AC to not kick on?

Power issues: A tripped circuit breaker or blown fuse in your home's electrical system will prevent your AC from starting. Thermostat problems: Make sure you have your thermostat set to “cool” and the temperature is set below the current temperature in the room.

How to tell if an AC capacitor is bad?

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.

Can the AC run without the outside unit running?

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.

Why won't my AC unit kick on the outside?

This could be due to a bad electrical connection, an overheated motor or a short circuit. To check the circuit breaker, locate it in your home's circuit breaker box and look for a tripped breaker, which will be in the center position between on and off. Reset the breaker and see if your AC works again.

How do I know if my outside AC fuse is blown?

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.

Should the outside fan run when AC is on?

The short answer: Definitely not. (Unless you have manually engaged your outside fan to run constantly, but it shouldn't be running for hours on it's own.) If your HVAC is functioning correctly, it should keep your house cool by cycling on for 15-20 minutes at a time—with distinct pauses in between each cycle.

Why is my AC unit running inside but not outside?

If you find that the inside part of your AC is buzzing along but the outside unit isn't cooperating, there's a chance that the issue could be as simple as a lack of power. Power issues are not uncommon, and they can occur for various reasons, including a flipped disconnect switch or potential wiring problems.

Why is my outside AC not turning on?

To fix this issue, you will need to reset the circuit breaker by switching it off and then back on again. If this doesn't work, then you may need to check for any loose or corroded wiring connections, replace any faulty fuses or circuit breakers, and ensure that your AC system is getting enough power supply.

How do I get my AC to kick on?

Follow these steps.
  1. Step 1: Check the thermostat. Make sure that your thermostat is set to "cool" and not "heat" (if it's set to heat, your AC won't turn on no matter what). ...
  2. Step 2: Check the air filter. ...
  3. Step 3: Check the circuit breakers. ...
  4. Step 4: Clear the condensate drain.

How to reset AC unit outside?

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.

How do I know if my AC condenser is clogged?

This article will discuss five signs your AC condenser needs repair.
  1. Bad Smell. When an AC condenser unit stays for long without maintenance, it may start emanating a foul odor. ...
  2. Lack of Cool Air. ...
  3. Burning Smell. ...
  4. Lack of Airflow. ...
  5. Overheating While Idling. ...
  6. Bad Smell. ...
  7. Lack of Cool Air. ...
  8. Burning Smell.

Why is my AC compressor not kicking on?

You'll want to have the unit examined for signs of a blown fuse, tripped circuit breaker, broken thermostat, or dirty air filters. Dirty or clogged filters commonly make AC compressors stop working. When it comes to operating your cooling system properly, be realistic with the temperature setting on your thermostat.

Do all AC units have a reset button?

Steps To Follow While Resetting Air Conditioner

One wrong step can cause greater damage. For this reason, follow a pattern while resetting your AC. Some ACs come with a reset button, while some don't. Most of the split AC systems have a reset button.

Can resetting the breaker fix AC?

In the majority of cases, your AC system will return to functioning normally after this breaker reset. It's important to know that this isn't an instant fix and may take up to an hour to get back up and running as normal again.

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