As a homeowner, you rely on your HVAC system to keep your home comfortable and safe year-round. However, like any mechanical system, HVAC systems can experience problems and malfunctions over time. From strange noises and insufficient heating or cooling to poor air quality and high energy bills, there are many potential signs that your HVAC system may be in need of repairs or maintenance.

In this blog post, we’ll discuss how HVAC professionals diagnose common HVAC problems, the tools and equipment they use, and the steps you can take as a homeowner to troubleshoot and diagnose basic problems on your own.

Common HVAC Problems

Before diving into the diagnostic process, it’s important to understand some of the most common HVAC problems homeowners may experience. These include:

Insufficient heating or cooling: If your HVAC system is not maintaining a consistent temperature in your home, there may be a problem with the thermostat, ductwork, or refrigerant levels.

Poor air quality: If you’re experiencing poor indoor air quality, such as dust, mold, or unpleasant odors, there may be issues with your HVAC system’s air filter or ventilation system.

Strange noises: If you’re hearing unusual noises coming from your HVAC system, such as clanging, rattling, or squealing, there may be problems with the blower motor, fan, or other components.

High energy bills: If your energy bills have suddenly increased without a corresponding change in your usage, there may be issues with your HVAC system’s efficiency or performance.

HVAC Diagnostic Tools

When HVAC professionals arrive to diagnose a problem, they often use a variety of tools and equipment to accurately assess the system. Some common diagnostic tools include:

Multimeters: These devices measure electrical current and voltage, allowing technicians to determine whether there are any electrical problems with the system.

Infrared thermometers: These tools measure temperature variations, helping technicians identify whether there are any hot or cold spots in the system.

Refrigerant gauges: These gauges measure the refrigerant levels in the system, which can help diagnose problems with cooling performance.

In addition to these tools, HVAC technicians may also use specialized diagnostic equipment, such as combustion analyzers or flow hoods, to identify more complex problems.

HVAC Diagnostic Process

Once the HVAC technician arrives and has the appropriate tools on hand, they will typically begin the diagnostic process by performing a thorough inspection of the system. This inspection may include the following:

Checking the thermostat: The technician will check that the thermostat is set correctly and functioning properly.

Checking the air filter: A dirty air filter can cause a variety of HVAC problems, so the technician will inspect and change the air filter if needed.

Checking the ductwork: The technician will inspect the ductwork for leaks, damage, or blockages that may be affecting HVAC performance.

Testing the electrical components: The technician will use a multimeter to test the electrical components of the system, such as the blower motor, capacitor, and control board.

Checking the refrigerant levels: The technician will use refrigerant gauges to measure the refrigerant levels and ensure that they are within the manufacturer’s recommended range.

If the inspection does not reveal the source of the problem, the technician will move on to more advanced diagnostic techniques, such as using infrared thermometers or specialized diagnostic equipment. Ultimately, the goal is to identify the underlying cause of the HVAC problem so that it can be addressed effectively.

DIY HVAC Troubleshooting

While it’s always best to leave HVAC repairs and maintenance to the professionals, there are some basic troubleshooting steps that homeowners can take to diagnose minor problems on their own. These may include:

Checking the thermostat settings: Make sure that the thermostat is set to the correct temperature and mode (heat or cool).

Checking the air filter: Inspect the air filter for dirt and debris, and replace it if necessary.

Checking the circuit breaker: If the HVAC system is not turning on at all, check the circuit breaker to ensure that it hasn’t tripped.

Inspecting the ductwork: Check the ductwork for any visible damage, such as holes or leaks, that may be affecting airflow.

However, it’s important to remember that HVAC systems can be complex and potentially dangerous, so homeowners should exercise caution when attempting DIY repairs or maintenance.

When to Call a Professional

While some HVAC problems can be easily diagnosed and fixed with basic troubleshooting, other issues require the expertise of a professional HVAC technician. Some signs that it’s time to call in the pros include:

Major repairs: If the problem is significant, such as a broken compressor or refrigerant leak, it’s best to call a professional rather than attempt a DIY repair.

Complicated diagnostic procedures: If the problem is complex and requires specialized diagnostic equipment or expertise, a professional technician is best equipped to handle it.

Safety concerns: HVAC systems involve electricity, natural gas, and potentially hazardous chemicals, so it’s important to leave repairs and maintenance to the professionals to avoid injury or property damage.

Benefits of Hiring a Professional

When you hire a professional HVAC technician to diagnose and repair your system, you’ll enjoy a range of benefits, including:

Expertise: Professional technicians have the training, experience, and expertise needed to accurately diagnose and repair HVAC problems.

Efficiency: Professionals have the tools and equipment needed to diagnose and repair problems quickly and efficiently, saving you time and money in the long run.

Warranties and guarantees: Many HVAC companies offer warranties or guarantees on their services, giving you peace of mind and protection against future problems.


In conclusion, diagnosing HVAC problems can be a complex process that requires the right tools, equipment, and expertise. Whether you’re troubleshooting minor problems on your own or calling in the professionals for major repairs, it’s important to take proactive steps to address HVAC problems and ensure that your system is functioning at peak performance. By understanding the diagnostic process and when to call in the pros, you can keep your home comfortable and safe year-round. If you need help with your HVAC system, don’t hesitate to contact Lithia Springs HVAC for professional assistance.