We’ve talked a lot about the crucial role that capacitors play in the operation of AC units, but why do AC capacitors go bad? Your AC unit is one of the most important parts of your home in SWFL, so preventing break downs is in every homeowner’s best interest. So let’s talk about your AC capacitor, what makes it last, and what makes it go bad. 

What Does an AC Capacitor Do?

An AC capacitor is responsible for storing and releasing electrical energy to power the compressor and the fan motors. Without capacitors, your AC unit wouldn’t be able to start or run efficiently. Capacitors are like little energy storage banks of your AC system. They provide the necessary power boost to get the motor running and maintain a steady flow of electricity. So, it’s clear that capacitors are essential components that ensure the smooth and efficient operation of your AC unit.

Types of Capacitors Found in AC Units

When it comes to AC units, there are different types of capacitors that are commonly found. The most common types include start capacitors, run capacitors, and dual run capacitors. Start capacitors are responsible for providing an extra boost of power to help start the motor, while run capacitors provide a steady flow of electricity to keep the motor running efficiently. Dual run capacitors combine the functions of both start and run capacitors, making them versatile for different AC units. Understanding the different types of capacitors can help homeowners identify and address specific capacitor-related issues in their AC units.

Why Do AC Capacitors to Go Bad

Capacitors can go bad for a variety of reasons. These are the most common reasons for air conditioner capacitor failure.


The main factor that causes AC capacitors to go bad is age. AC capacitors have a limited lifespan and will eventually wear out over time, but other factors 

Extreme temperatures

Extreme temperatures can also contribute to capacitor failure, especially if they are constantly exposed to heat or cold. In SWFL, a start capacitor, run capacitor, or dual run capacitor in an HVAC system is used excessively because of consistent extreme temperatures. 

Power surges

Another factor is voltage spikes or bursts of energy, which can damage the internal components of the capacitor. Since an AC’s capacitor stores electrical energy, a power surge or electrical charge can easily damage this part. 

Poor maintenance

Poor AC maintenance can also lead to capacitor failure. If your HVAC unit doesn’t get much attention and care, it can easily end up running inefficiently, which means your AC capacitor has to work harder, and more regularly. 

Bad AC Capacitor Symptoms

If you’re experiencing issues with your AC unit, it’s important to know the symptoms of a bad or broken capacitor. One common sign is difficulty starting the unit, where you may hear a humming sound but the motor doesn’t turn on. Another indicator is a weak airflow, where the air coming out of the vents feels weaker than usual. You may also notice frequent tripping of the circuit breaker or inconsistent cooling and even rising energy bills. A humming noise coming from your outside unit can also be a sign of an old capacitor getting ready to give out. If you notice any of these symptoms, it’s a good idea to have your AC capacitor checked by a professional to prevent further damage.

Common Mistakes That Can Damage a Capacitor

When it comes to AC capacitors, there are a few common mistakes that homeowners make that can lead to damage. One of the biggest mistakes is improper installation. If a capacitor is not installed correctly, it can cause stress on the internal components and lead to premature failure. Another mistake is neglecting regular maintenance. AC units require routine maintenance to ensure optimal performance, and neglecting this can put a strain on the capacitor. Using the wrong size or type of capacitor can also cause damage. It’s important to consult a professional and follow the manufacturer’s guidelines to avoid these common mistakes and keep your AC capacitor in good shape.

Tips for Preventing Capacitor Failure in an AC Unit

Proper maintenance and care are key to preventing capacitor failure in your AC unit. Here are some helpful tips to keep your capacitor in good shape. 

Schedule regular professional maintenance

Always have a plan for maintenance for your AC unit. This will include cleaning and inspecting the capacitor to catch any potential issues before they become major problems. 

Avoid overworking your AC unit 

You can take some of the load off of your AC unit by setting the thermostat at a moderate temperature and giving your unit breaks between cooling cycles. 

Protect your AC unit from extreme temperatures

Your AC will have to work hard in the SWFL heat, but you can help protect it by providing shade or insulation for the outside unit. 

Always consult a professional for proper installation

Having a failed capacitor issue because of improper installation can easily be avoided. Not only is it a good idea to have your replacement capacitor installed by a professional so that it works properly, but it’s also really important for your safety. Since the capacitor stores energy and is high voltage, the electrical system of the air conditioner’s capacitor should only be handled by a trained professional.

Do You Need a New Capacitor?

If you think you have a faulty capacitor after learning the most common reasons they go bad and the symptoms of a bad capacitor, it’s time to contact the professionals to verify your suspicions. Your air conditioning system could have other issues that are causing the symptoms, so a Dolphin technician will diagnose the AC problem and its exact cause before going straight to capacitor replacement. It’s important to have a professional HVAC technician present because they are trained to handle the various components of your air conditioner unit safely and get it back up and running quickly!

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