Window Unit Ac Compressor Wont Kick On

Introduction

A window air conditioner that isn’t cooling your room on a hot day is frustrating. Often, the reason is that the compressor isn’t starting or “kicking on.” The compressor is the heart of your AC unit; it’s responsible for circulating the refrigerant that cools the air. If it’s not working, your AC will blow air, but it won’t be cold. This can happen due to various reasons, and it’s important to address it promptly to prevent further damage to your AC unit and to restore comfortable temperatures in your home. Finding the cause and fixing it yourself can save you money and time before calling a professional.

Common Causes of window unit ac compressor wont kick on

Here are some common reasons why your window AC compressor might not be starting:

• Power Issues: The AC isn’t receiving power, due to a tripped breaker, a blown fuse, or a faulty power cord.
• Thermostat Settings: The thermostat isn’t set low enough or isn’t calling for cooling.
• Dirty Air Filter: A clogged air filter restricts airflow, causing the unit to overheat and the compressor to shut down as a protective measure.
• Frozen Evaporator Coils: Restricted airflow can cause the evaporator coils to freeze, preventing the compressor from starting.
• Overload Protector Tripped: The overload protector is designed to shut down the compressor if it gets too hot.
• Capacitor Problems: The capacitor provides the initial jolt of electricity needed to start the compressor. If it’s weak or damaged, the compressor won’t start.
• Dirty Condenser Coils: Dirty condenser coils prevent the unit from properly releasing heat, causing it to overheat and the compressor to fail.
• Faulty Compressor: In rare cases, the compressor itself may be faulty and require replacement.

Symptoms Checklist

Check the following to accurately identify the issue:

• The AC unit turns on, but only blows warm air.
• You hear a humming sound, but the compressor doesn’t start.
• The AC unit shuts off shortly after turning it on.
• The overload protector trips frequently.
• The air filter is visibly dirty or clogged.
• Ice is forming on the evaporator coils (usually visible with the front panel removed).

How to Fix window unit ac compressor wont kick on Step-by-Step Guide

Follow these steps to troubleshoot and potentially fix the issue:

1. Check the Power Cord: Make sure the power cord is securely plugged into the outlet.
2. Test the Outlet: Use a lamp or other small appliance to verify the outlet is working.
3. Check the Breaker/Fuse: Go to your circuit breaker box and check if the breaker for the AC unit has tripped. Reset it if necessary. If you use fuses, check that the fuse isn’t blown.
4. Adjust Thermostat: Ensure the thermostat is set to “Cool” and the temperature is set lower than the current room temperature.
5. Clean the Air Filter: Remove the air filter and clean it thoroughly with soap and water. Allow it to dry completely before reinstalling.
6. Check for Frozen Coils: If you see ice forming on the evaporator coils (behind the filter), turn off the AC unit and allow the ice to melt completely. This may take several hours. Ensure the air filter is clean when you restart it.
7. Reset the Overload Protector: Some AC units have a reset button on the overload protector. Look for a small button on the back or side of the unit and press it.
8. Clean the Condenser Coils: Unplug the AC unit. Use a brush or vacuum with a brush attachment to gently clean the condenser coils on the back of the unit.
9. Inspect the Capacitor (Caution: Requires Knowledge of Electrical Safety): Only if you are comfortable and familiar with electrical safety, carefully inspect the capacitor (usually a cylindrical component) for signs of bulging, leaking, or other damage. If it looks damaged, it likely needs replacing, and you may want to consult a professional.
10. Give it a Rest: Sometimes, the compressor just needs a break. Turn off the unit and unplug it for a few hours, then try again.
11. Listen Carefully: When you turn the AC on, listen closely for any clicking or humming sounds that might indicate the compressor is trying to start but failing. This could point to a capacitor issue.
12. Check the Unit Angle: Ensure the AC unit is slightly tilted to the outside. This helps with drainage and prevents water buildup, which could interfere with the compressor operation.

Fix the Issue Without Buying Parts

Here are some free ways to troubleshoot the problem:

• Reset the AC Unit: Unplug the unit for 15-20 minutes to allow the system to completely reset itself.
• Thorough Cleaning: A deep clean can resolve many airflow and overheating issues. Focus on the filter and coils.
• Inspection Tips: Regularly inspect the unit for any signs of damage, leaks, or obstructions.
• Maintenance Basics: Clean the air filter every month, and the coils at least twice a year, to ensure optimal performance.

When Replacement Might Be Necessary

If you’ve tried all the troubleshooting steps and the compressor still isn’t working, it might be time to consider replacing the unit, especially if the unit is old. The compressor itself can be replaced, but the cost often approaches or exceeds the cost of a new unit.Estimated costs (USD):

• New Window AC Unit: $150 – $500 (depending on size and features)
• Compressor Replacement (labor and parts): $200 – $400 (may not be worthwhile on older/smaller units).

Commonly failing parts besides the compressor include the capacitor and the overload protector.

Safety Warning

• Always unplug the AC unit before performing any maintenance or repairs.
• Avoid working on electrical components if you are not comfortable or experienced.
• Never work on the AC unit with wet hands or while standing on a wet floor.
• If you suspect a refrigerant leak, ventilate the area and contact a qualified technician.

Tools You May Need

• Screwdriver (Phillips and flathead)
• Vacuum cleaner with brush attachment
• Soft brush
• Multimeter (for testing electrical components – use with caution and proper knowledge)
• Pliers

FAQ

Q: Why does my AC unit blow warm air even though it’s turned on? A: This usually means the compressor isn’t working, preventing the refrigerant from cooling the air. Refer to the troubleshooting steps above. Q: How often should I clean the air filter? A: Clean the air filter every month, or more often if you have pets or allergies. Q: What does the capacitor do? A: The capacitor provides the initial surge of power needed to start the compressor motor. Q: Is it worth repairing a window AC unit? A: It depends on the age and cost of the unit, and the extent of the repair. If the compressor itself is failing, replacement is often more cost-effective. Q: Can a dirty filter cause the compressor not to start? A: Yes. A dirty filter restricts airflow, which can lead to overheating and prevent the compressor from starting, or even cause damage. Q: How do I know if the overload protector is tripped? A: The unit will not turn on, and you may find a small reset button on the back or side of the unit.

Conclusion

Troubleshooting why your window AC compressor won’t kick on can seem intimidating, but by following these steps, you can often identify and resolve the issue yourself. Remember to prioritize safety and to regularly maintain your AC unit to prevent future problems. If you’ve exhausted these steps and the problem persists, it’s best to call a qualified appliance repair technician for further assistance. Don’t give up before trying these easy steps!

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