how to clean ac contactor



Cleaning the AC contactor is an essential part of maintaining your air conditioning system. Over time, the contactor can accumulate dirt, dust, and debris, hindering its functionality and efficiency. Regular cleaning not only improves the performance of your AC but also extends its lifespan. In this article, we will provide you with a comprehensive guide on how to clean the AC contactor effectively. Whether you are a DIY enthusiast or a homeowner, these techniques will help you keep your AC running smoothly.

Understanding the AC Contactor:

AC contactor, also known as a relay, is a critical component of your air conditioning system. Its primary function is to control the flow of electricity to the various parts of the system. When the thermostat signals the need for cooling, the contactor is responsible for activating the compressor and fan motor. Over time, the contactor can suffer from wear and tear, and dirt and debris can hinder its performance. Cleaning the AC contactor ensures proper electrical connections and prevents any potential damage.

Tools and Safety Precautions:

Before we dive into the cleaning process, it is important to gather the necessary tools and take some safety precautions. Here's what you'll need:

1. Screwdriver (Flathead or Phillips, depending on the contactor screws)

2. Disposable gloves

3. Safety goggles

4. Non-conductive brush or a soft-bristled brush

5. Compressed air canister or a vacuum with a brush attachment

6. Contact cleaner (optional)

7. Plastic bag or container for removed screws

8. Turn off the power: Before you start working on your AC contactor, ensure that the power to the system is turned off. This prevents any accidental electrical shocks and potential damages to the system.

9. Safety goggles and gloves: Always wear safety goggles and disposable gloves to protect yourself from any debris or cleaning chemicals that may come in contact with your eyes or skin.

10. Handle with care: The contactor's components are delicate and sensitive. Handle the parts with care to avoid any damages.

Cleaning the AC Contactor Step by Step:

Now that we understand the significance of the AC contactor and have taken the necessary precautions, let's dive into the step-by-step process of cleaning the AC contactor:

Gaining Access to the Contactor:

To clean the AC contactor, you need to locate it first. Here's how you can find the contactor:

1. Turn off the power: Ensure that the power to the air conditioning system is turned off from the electrical panel.

2. Remove the access panel: Use a screwdriver to remove the screws securing the access panel. Carefully place the removed screws in a plastic bag or container to avoid misplacing them.

3. Locate the contactor: The contactor is usually a black or gray box with multiple wires attached to it. It is typically located near the condenser unit or the outdoor part of the air conditioning system.

Inspecting for Damage:

Before starting the cleaning process, it's crucial to inspect the contactor for any visible signs of damage or wear. Here's what you should look for:

1. Burned or melted contacts: The electrical contacts inside the contactor should be clean and intact. If you notice any signs of burn marks or melting, it indicates a potential problem, and the contactor may need to be replaced.

2. Loose or damaged wires: Check the wires connected to the contactor for any loose connections or signs of damage. Ensure that all the wires are securely fastened to the appropriate terminals.

3. Debris or dust accumulation: Examine the contactor for any visible debris or dust buildup. While some accumulation is normal, excessive dirt can hinder the contactor's functionality.

Cleaning the Contactor:

Once you have inspected the contactor and ensured that there are no significant damages, you can proceed with the cleaning process. Follow these steps:

1. Remove the contactor: Carefully detach the contactor from its position by removing the screws holding it in place. Place the screws in a safe container.

2. Clean the outer surfaces: Using a soft-bristled brush, gently remove any loose dirt or debris from the contactor's outer surfaces. Be thorough but gentle to prevent any damage to the delicate components.

3. Compressed air or vacuum: Utilize compressed air or a vacuum cleaner with a brush attachment to remove any remaining dust or debris. Direct the air or vacuum carefully to avoid displacing any small parts.

4. Inspecting the contacts: Examine the electrical contacts for any signs of corrosion or buildup. If you notice any visible contamination, use a non-conductive brush or a cotton swab dipped in contact cleaner to clean the contacts. Be cautious not to bend or damage the contacts during cleaning.

Reassembling and Testing:

After thoroughly cleaning the AC contactor, it's time to reassemble it and ensure that it functions properly. Follow these steps:

1. Place the contactor back: Carefully position the contactor back in its original position and secure it with the screws. Ensure that the contactor is fitted correctly and aligned with the corresponding wires.

2. Reattach the access panel: Place the access panel back in its position and securely fasten it with the screws. Double-check to ensure that all screws are tightened correctly.

3. Power on the system: Go to the electrical panel and turn on the power to the air conditioning system.

4. Test the AC: Set your thermostat to a cooling mode and observe if the AC turns on. Pay attention to any unusual sounds or behaviors. If you notice any issues, it's advisable to contact a professional technician for further assistance.

Regular Maintenance and Cleaning Tips:

Cleaning the AC contactor should be a part of your regular air conditioning maintenance routine. Here are some additional tips to keep your AC contactor in optimal condition:

1. Clean the contactor annually: Schedule a yearly cleaning for your AC contactor to prevent dirt and debris buildup. This will ensure that your system runs efficiently and smoothly.

2. Trim vegetation around the outdoor unit: Regularly trim any nearby shrubs or plants around your outdoor unit to prevent debris accumulation and promote good airflow.

3. Keep the unit elevated: Raise the condenser unit slightly above ground level to minimize dust and dirt infiltration. This can be achieved by using a dedicated concrete pad or approved risers.

4. Change air filters regularly: Clogged and dirty air filters can contribute to the accumulation of dirt on the contactor. Follow the manufacturer's recommendations and replace the air filters at regular intervals.

5. Professional maintenance: While you can perform basic cleaning and maintenance, it's recommended to schedule professional AC maintenance annually. A technician can inspect and clean the entire system, ensuring its optimal performance.


Regularly cleaning the AC contactor is a simple yet crucial step in maintaining the efficiency and longevity of your air conditioning system. By following the step-by-step guide provided in this article, you can ensure that your AC contactor remains free from dirt, debris, and potential damages. Remember to take the necessary safety precautions, follow the manufacturer's instructions, and seek professional help when needed. By keeping your AC contactor clean, you contribute to a comfortable and well-functioning cooling system in your home or office.


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