Ac Unit Won T Turn On Outside

Introduction

Is your air conditioner blowing hot air, or worse, not turning on at all? If the outdoor unit (the condenser) refuses to kick on, it can quickly turn your comfortable home into a sweltering sauna. This problem is common during peak summer months when AC units are working overtime. Getting your AC running is crucial, not just for comfort, but also to prevent potential health issues related to overheating, especially for children and the elderly. Lets troubleshoot and get your AC back in action!

Common Causes of ac unit won t turn on outside

Here are some common reasons why your outside AC unit might not be turning on:

• Tripped Circuit Breaker: An overload can cause the breaker dedicated to the AC to trip.
• Disconnected Power: The outdoor unit may have a dedicated disconnect switch that has been accidentally turned off.
• Dirty Condenser Coils: Dust, leaves, and debris can clog the coils, preventing proper cooling and potentially shutting down the unit.
• Failed Capacitor: Capacitors provide the initial jolt of power to start the motor. A failing capacitor is a common culprit.
• Faulty Contactor: The contactor is an electrical switch that sends power to the compressor and fan motor. A bad contactor won’t deliver power.
• Overheating: The unit may be overheating and triggering a safety shut-off.
• Frozen Evaporator Coil: If the inside evaporator coil freezes, it can prevent the outdoor unit from starting (usually due to airflow issues inside).
• Refrigerant Leak: Low refrigerant can cause the unit to shut down to prevent damage to the compressor.
• Bad Fan Motor: If the fan motor is broken, the unit can overheat and shut down.

Symptoms Checklist

Check these indicators to accurately identify the issue:

• No sound coming from the outdoor unit when the thermostat is set to cool.
• The indoor fan (blower) is running, but the outdoor unit is silent.
• You hear a humming sound from the outdoor unit, but the fan isn’t spinning.
• The circuit breaker for the AC keeps tripping.
• Visible ice buildup on the refrigerant lines or the outdoor unit itself.
• The fan blades are obstructed by debris.

How to Fix ac unit won t turn on outside Step-by-Step Guide

Follow these steps to troubleshoot your AC unit:

1. Check the Thermostat: Make sure your thermostat is set to “Cool” and the temperature is set lower than the current room temperature. Verify that the thermostat display is on and working.
2. Check the Circuit Breaker: Locate the breaker labeled “AC” or “Air Conditioner” in your electrical panel. If it’s tripped (in the middle position), flip it all the way to the “Off” position and then back to “On.”
3. Check the Disconnect Switch: Find the disconnect switch near the outdoor unit. It’s usually a gray box with a handle or a pull-out block. Ensure it’s in the “On” position or the block is fully inserted.
4. Inspect the Condenser Coils: Carefully examine the outside of the unit for any visible debris like leaves, grass clippings, or cottonwood. Use a garden hose (with a gentle spray nozzle) to clean the coils from the inside out. Avoid high pressure, which can damage the fins.
5. Check for Ice Buildup: Look for ice on the refrigerant lines or the outdoor unit itself. If you see ice, turn off the AC and just run the inside fan for a few hours to melt the ice. The issue is likely restricted airflow inside.
6. Inspect the Fan Blades: Make sure the fan blades are free of obstructions and can spin freely. Remove any debris that might be blocking them.
7. Listen for Humming: If you hear a humming sound from the unit but the fan isn’t spinning, the capacitor may be failing. Note: this is something best left to a professional.
8. Check the Air Filter: A dirty air filter restricts airflow and can cause the evaporator coil to freeze. Replace your air filter regularly (every 1-3 months). The filter is inside by the indoor AC unit.
9. Inspect the Return Air Vents: Make sure your return air vents inside the home are not blocked by furniture or rugs. Good airflow is crucial for proper AC operation.
10. Wait and Restart: After checking and cleaning, wait about 30 minutes and try turning the AC back on. The unit may have a built-in overload protection that needs time to reset.

Fix the Issue Without Buying Parts

Here are some free methods to try before considering replacements:

• Resetting: Simply turning off the AC at the breaker for 30 minutes can sometimes reset the system.
• Cleaning: Regular cleaning of the condenser coils and replacing the air filter can prevent many issues.
• Inspection: Regularly inspect the unit for any signs of damage or debris buildup.
• Maintenance Basics: Keep the area around the outdoor unit clear of vegetation and obstructions.

When Replacement Might Be Necessary

If the above steps don’t work, you might need to consider replacing parts. A common failing part is the capacitor (estimated cost: $50-$150 installed), or the contactor switch (estimated cost: $100-$250 installed). If the compressor is failing, replacing the entire unit might be more cost-effective (estimated cost: $3,000 – $7,000 installed). For more related activities, check out our My Hvac Is Not Cooling.

Safety Warning

• Always turn off the power to the AC unit at the circuit breaker before performing any maintenance or inspection.
• Avoid touching any electrical components with wet hands or while standing in water.
• If you are not comfortable working with electricity, call a qualified HVAC technician.

Tools You May Need

• Screwdriver (Phillips and Flathead)
• Garden Hose with Spray Nozzle
• Work Gloves
• Multimeter (for testing electrical components – use only if you are comfortable with electrical testing)

FAQ

Here are some frequently asked questions:

• Q: Why is my AC blowing warm air? A: This could be due to a refrigerant leak, a dirty air filter, or a malfunctioning compressor.
• Q: How often should I clean my AC coils? A: At least once a year, preferably before the start of the cooling season.
• Q: What does a failing capacitor sound like? A: It might sound like a humming or buzzing noise.
• Q: Can I fix a refrigerant leak myself? A: No, refrigerant handling requires specialized equipment and certification. Contact a qualified technician.

Conclusion

Troubleshooting your AC unit can seem daunting, but by following these steps, you can often identify and fix the problem yourself. Before calling a technician, take the time to check the basics. You might be surprised at how often a simple fix can get your AC running smoothly again. If you’re still having trouble, don’t hesitate to contact a qualified HVAC professional for assistance.

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