how to reset ac contactor


How to Reset AC Contactor


The AC contactor is a crucial component in your air conditioning system that controls the flow of electricity to the compressor and the condenser fan motor. Over time, due to wear and tear, electrical surges, or other factors, the contactor may require resetting to ensure proper functioning and prevent any potential issues. Resetting the AC contactor can be done without professional help, saving you time and money. In this article, we will guide you through the process of resetting the AC contactor to restore your air conditioning system's optimal performance.

Understanding the AC Contactor

The AC contactor is an electrical switch that allows or interrupts the power flow to the air conditioning system components. It consists of a coil, relay contacts, and terminals. When activated, the coil creates a magnetic field that pulls the relay contacts together, allowing the electricity to flow through. This, in turn, powers the compressor and the condenser fan motor. The contactor plays a crucial role in the operation of the air conditioning system and needs to function correctly for efficient cooling.

Signs of a Malfunctioning AC Contactor

Before jumping into the process of resetting the AC contactor, it's important to identify potential signs of a malfunctioning contactor. By recognizing these signs, you can determine whether the contactor reset is necessary. Here are some common indicators of a malfunctioning AC contactor:

1. Intermittent Cooling: If your air conditioning system starts and stops frequently or fails to cool consistently, it may be due to a faulty contactor.

2. Clicking Sound: A clicking sound coming from the contactor when the system cycles on and off is a sign of a potential contactor issue.

3. Burn Marks: Physical inspection of the contactor may reveal burn marks or signs of damage, indicating a need for reset or replacement.

4. Inconsistent Electrical Flow: If you notice fluctuations in the electrical current supplied to the system, it may indicate a faulty contactor.

5. System Failure: In extreme cases, a malfunctioning contactor can result in complete system failure, where your air conditioner fails to operate altogether.

By keeping an eye out for these signs, you can catch contactor issues early on and resolve them promptly.

Resetting the AC Contactor

Before attempting to reset the AC contactor, it is crucial to ensure your safety by following some precautions. Make sure to turn off the power to your air conditioning system by switching off the circuit breaker related to it in your electrical panel. Additionally, wearing insulated gloves and using appropriate tools will help protect you from any potential electrical hazards during the process. Once you have taken necessary safety measures, follow the step-by-step guide below to reset your AC contactor effectively:

1. Locating the Contactor: The contactor is usually found in the outdoor unit of your air conditioning system. It is a box-shaped component with several wires connected to it.

2. Inspecting the Contact Points: Thoroughly examine the contact points on the contactor for any signs of corrosion, dirt, or burn marks. If you observe any of these, clean the points using a wire brush or a clean cloth. Ensure all the connections are secure.

3. Resetting the Contactor: Once the contact points are clean, gently push the contactor relay switch to reset the component. Apply a small amount of pressure to ensure it is fully engaged.

4. Powering On the System: After resetting the contactor, wait for a few minutes and then restore power to your air conditioning system by switching on the circuit breaker.

5. Testing the AC Contactor: Turn on your air conditioning system and observe its operation. Check if the compressor and the condenser fan motor are functioning as expected. If the system runs smoothly without any issues, your contactor reset was successful.

Maintaining the AC Contactor

Resetting the AC contactor can solve many common issues, but proper maintenance can help prevent future problems. Regular maintenance will prolong the lifespan of the contactor and ensure continued efficient cooling. Here are some maintenance tips to consider:

1. Cleanliness: Keep the outdoor unit clean and free from debris, such as leaves, dirt, and twigs. Regularly clean the contactor to prevent dirt buildup.

2. Inspection: Periodically inspect the contactor for signs of wear, corrosion, or damage. If you notice any issues, address them promptly.

3. Electrical Testing: Schedule regular professional electrical testing to ensure the contactor is functioning correctly and is within the recommended safety parameters.

4. Professional Servicing: Consider regular professional servicing of your air conditioning system to identify and resolve any underlying issues with the contactor or other components.

5. Replacement: If your contactor continues to malfunction despite resetting and maintenance, it may be time to replace it. Consult a qualified HVAC technician for guidance and assistance.


Resetting the AC contactor is a straightforward process that can easily be done by following the steps mentioned above. By identifying signs of a malfunctioning contactor and taking timely action, you can avoid costly repairs and ensure optimal performance of your air conditioning system. Remember to prioritize safety precautions when working with electrical components and always consult a professional if needed. Regular maintenance and care will keep your contactor in good condition, contributing to the longevity and efficiency of your air conditioning system.


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