Should I Test My HVAC Capacitor or Call a Professional?

Professional-grade maintenance of your HVAC system involves paying attention to many different components, systems, connections and moving parts. Even homeowners who understand the basics or principles of air conditioner operations likely don’t have years of experience maintaining, diagnosing and repairing all the parts of their HVAC system. 

Knowing what an HVAC capacitor does and recognizing the symptoms of a failing capacitor is one thing. Having the necessary equipment and experience to safely test capacitors, interpreting the results in the context of the system’s age and performance and formulating a repair plan typically requires more experience than even DIY-inclined homeowners possess.

If you are thinking about testing your capacitor, it’s important to know the risks involved with testing it yourself.

What Is an HVAC Capacitor?

An HVAC capacitor is a small but essential component within your HVAC system. It functions as a stored energy reservoir that helps start and run the motors within your system, such as those in the compressor, condenser fan and blower motor.

The capacitor stores electrical energy and releases it when needed to keep the motors operating smoothly. It’s vital to the functioning of your HVAC system, and your system will stop working altogether if the capacitor fails completely.

Capacitor failure can take many forms, including gradual decline, sudden failure and intermittent failure. Your system will display different performance symptoms depending on the condition of your capacitor, which may allow you to at least recognize there is a problem ahead of total failure.

Symptoms of a Failing Capacitor

• Unusual Noises: If you hear buzzing or humming noises coming from your HVAC system, it could indicate a problem with the capacitor. A failing capacitor may struggle to start the motors, leading to these unusual sounds.
  
  
• System Struggles to Start: If your HVAC system has trouble starting up or takes longer than usual to get going, a failing capacitor might be the culprit. The capacitor helps kickstart the motors. If it's not functioning correctly, it can cause delays or prevent the system from starting altogether.
  
  
• Inconsistent Cooling or Heating: Inconsistent temperature control or fluctuating cooling and heating can signal a problem with the capacitor. When the capacitor is only working intermittently, it can cause the system to cycle unpredictably, leading to uneven temperatures.
  
  
• Electrical Smells: If you notice a burning or electrical smell near your HVAC system, it could be due to a malfunctioning capacitor. This is a sign that the capacitor may be overheating or failing.

Testing an HVAC Capacitor

Testing an HVAC capacitor involves measuring its capacitance using a multimeter, which requires specialized knowledge and tools. The process an HVAC technician will follow typically includes:

1. Power Off: Before testing, it's important to turn off the power to the HVAC system at the circuit breaker for safety.
   
   
2. Discharge the Capacitor: Capacitors can store electrical energy even when the power is off, so discharging the capacitor is necessary to avoid electric shock.
   
   
3. Remove the Capacitor: The technician will carefully remove the capacitor from its mounting location. This step requires handling the component with care to avoid damage.
   
   
4. Measure Capacitance: The technician will use a multimeter’s capacitance measurement mode to measure the capacitor’s capacitance. They will compare the reading to the specifications on the capacitor's label to determine if it’s functioning correctly.
   
   
5. Reinstall or Replace: Based on the test results, they may either reinstall the capacitor or recommend replacing it if it’s found to be faulty. Testing capacitors is a fairly standard maintenance check, and a technician should be able to explain how your capacitor is performing compared to a new capacitor and what that means in terms of projected lifespan.

Why Should Homeowners Avoid Testing Their Own Capacitors?

While testing an HVAC capacitor might seem straightforward, there are several compelling reasons to leave this task to certified and insured HVAC professionals like our team at Tom’s Mechanical Inc.

First, capacitors can retain a charge even when the power is off, posing a risk of electrical shock. Certified HVAC technicians are trained to handle these components safely and are equipped with the appropriate tools and safety equipment to manage these risks effectively. In the unlikely event a technician is injured or damages the system when testing a capacitor, their insurance will protect you, the homeowner, from liability.

Capacitor warranties are often for five to 10 years, meaning you may be able to get a replacement before the capacitor fails without having to pay the part cost.

However, most HVAC warranties stipulate that the capacitor, along with other components, must be checked, serviced and replaced by a licensed or certified HVAC technician. Testing or replacing the capacitor yourself may void the warranty, leaving you responsible for the full cost of any future repairs or replacements.

Without proper training, you also risk causing additional damage to your HVAC system. Incorrect handling or installation of a new capacitor can result in bigger electrical issues and costly repairs, further complicating the situation.

Certified HVAC professionals possess the expertise to diagnose and address issues beyond just the capacitor. They can identify related problems and make sure your HVAC system operates efficiently as a whole, providing long-term benefits and peace of mind.

Get Comprehensive Services for Your Arlington, TX Air Conditioner

If you’re experiencing issues with your HVAC system or suspect a problem with your capacitor, don’t risk it. Our skilled technicians are equipped with the knowledge and tools to handle your HVAC needs safely and efficiently. From diagnosing issues to performing precise repairs, we make sure your system runs smoothly.

Contact us today at 817-277-4493 and let us take care of your HVAC needs with professionalism and care. Your comfort is our priority!