6 reasons why a window air conditioner blows the fuse or trips the circuit breaker

There may be nothing more frustrating than a window air conditioner that suddenly stops working due to a blown fuse or tripped circuit breaker in the middle of summer.

Before calling in an expensive technician, there are several troubleshooting steps you can take to resolve the problem on your own, which can save you time and money. Let’s walk through them together so you won’t be left sweltering in the heat.

If you find out that you need any replacement parts for your air conditioner while you’re troubleshooting, you can enter your model number at AppliancePartsPros.com to order them. Most orders arrive in just two business days, and we have thousands of free guides to show you how to install your new parts.

Important: The troubleshooting information provided in this article may not apply to your specific appliance model. While we strive to offer helpful advice for DIY appliance repairs, variations in models and configurations can lead to differences in troubleshooting steps, error codes and part replacements. For the most accurate guidance, we strongly recommend consulting the technical sheet for your specific appliance model.

Safety precautions

When working on any appliance, remember to keep safety first. Here are some tips to keep in mind:

• Always power off and unplug your appliance or switch off the circuit breaker before you attempt any maintenance or replacement work. This keeps you safe by eliminating any risk of electric shock.
• If the appliance has recently been used, give it plenty of time to cool down before working on it.
• Don’t test live voltage with a multimeter if you’re unfamiliar with how to prevent short-circuiting.
• Take your time while working to prevent accidents and personal injuries. Rushing is the enemy of precision.
• Work in a well-lit area so you can see and access appliance parts.
• Keep your workspace free of clutter and other obstacles. Keep children and pets away from the work area.
• Never work on internal parts with wet hands. Make sure the work area is completely dry.
• Check the user manual to see if there are specific installation or safety instructions related to your appliance or replacement part.
• Be gentle when handling or removing parts. Excessive force might damage the appliance or cause personal injury.
• Wear insulated work gloves to protect your hands from sharp metal parts and debris.
• When working with wires, avoid touching any exposed wires or terminals. If you need to touch a wire, use a non-conductive tool or wear insulating gloves to prevent electrical shock.
• Always take photos or make a note of wiring terminals or other connections before disconnecting them to make reassembly easier.

Read more: How to Clean Your Air Conditioner the Easy Way

Why a window air conditioner blows the fuse or trips the circuit breaker

Find out what’s causing your window AC to blow the fuse or trip the circuit breaker & how you can fix it yourself.

Reason #1: Unit was restarted too soon

Restarting the AC unit too soon after it has been turned off can cause the compressor to draw a high current spike, which can blow the fuse or trip the circuit breaker.

Wait at least 5 minutes before attempting to restart the air conditioner. This allows the compressor to cool down properly and the pressure to equalize before it restarts.

Reason #2: Overloaded circuit

• Make sure the air conditioner has a dedicated circuit.
• If the air conditioner has to remain on a circuit with other appliances, reduce the number of other power-drawing machines on the same circuit.
• Replace the blown fuse or reset the tripped circuit breaker.

Reason #3: Using the wrong fuse

Check that the fuse used for the window AC is a time-delay type that’s rated for the correct amperage to handle the air conditioner’s power draw. If you have a different type of fuse, replace it with the proper time-delay fuse that has the correct rating.

Read more: How to troubleshoot & fix common window air conditioner problems

Reason #4: Short-circuited cord or plug

1. Unplug the cord from the power outlet.
2. Inspect the power cord and plug (also called a power receptacle) for any visible damage, breaks, or signs of a short circuit. If the cord is damaged, replace it with a new one. If you suspect an electrical problem with the plug, contact a licensed electrician to resolve it.
3. Set a multimeter to continuity mode and use the probes to check the cord for continuity. The meter should make a beeping sound if there’s continuity. If there’s no continuity, replace the cord.

Reason #5: Short-circuited switch or motor

Use a multimeter set to continuity mode to test the continuity of the switches and the motor windings. The meter should make a beeping sound if there’s continuity. If any part shows an open circuit on a low-resistance circuit, you’ll need to replace it.

Reason #6: Wiring shorted or grounded against the frame

1. Inspect all the wiring connections inside the air conditioner for signs of shorting or grounding against the metal frame. If you see any signs of damage, replace the wiring.
2. Set a multimeter to continuity mode and use the probes to check for continuity between the wiring and the frame. The meter should make a beeping sound if there’s continuity. If there’s no continuity, replace the wiring.
3. Make sure all the wiring connections are secure and tighten any that are loose.
4. Check the insulation to make sure there aren’t any signs of wear or damage to it. Replace the insulation if needed.

Read more: How to get better air quality from your window air conditioner

Looking for more?

Thank you for reading! We hope this guide helped you get your window air conditioner working again.

If you have any other appliance repair needs or projects, don’t hesitate to explore our other troubleshooting guides and videos.

If you need replacement parts or some extra help with ordering them, grab your model number and head over to AppliancePartsPros.com, where you can chat with a pro, read our DIY blog and more.

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