top of page

HVAC Maintenance Guide: How to Keep Your HVAC System Running Smoothly

Gas furnace flames

HVAC maintenance is often overlooked. It is the last thing anyone wants to add to their yearly maintenance checklist. It is right up there with annual maintenance on a car. Like a car, an HVAC system has moving parts. These moving parts work together to ensure the home maintains comfortable temperatures. And they must be checked and maintained for the HVAC unit to work.

Yearly HVAC maintenance is an effective way to maximize the HVAC system's lifespan. And ensure it works efficiently. It helps ensure the heating and cooling systems work when needed. And it is an excellent way to stay on top of air filter changes.

This guide covers everything you need to know about HVAC maintenance. Including why HVAC maintenance is important, how often to do it, and what it includes.

Jump to Section

  1. Why HVAC maintenance is important

  2. When and how often should HVAC maintenance be done?

  3. What does HVAC maintenance include?

  4. Cooling system maintenance

  5. Heating system maintenance

  6. Ventilation system maintenance

  7. Ducting system maintenance

  8. Indoor air quality maintenance

  9. HVAC maintenance cost

  10. HVAC maintenance FAQ

  11. Conclusion

Why HVAC maintenance is important

HVAC includes heating, ventilation, and air conditioning. And consists of different parts, such as an outdoor and indoor unit. With coils, a compressor, fans, motors, filters, and other electronics. They all work together to control a home's temperature and indoor air quality. Any part within the HVAC system that doesn't work or shows signs of wear should be taken care of or replaced.

HVAC maintenance is essential for a few reasons. The first is to ensure the HVAC unit is working safely. The second is to ensure the system works at all. The third is to ensure the system works effectively and efficiently. And the fourth is to upkeep the HVAC systems warranty. Most HVAC system manufacturers require yearly maintenance to maintain the warranty.

HVAC maintenance can help prevent various problems with an HVAC system. Common problems include restricted air filters. Restricted indoor or outdoor coils, water leaks, faulty ac capacitors, and electronic failures. HVAC maintenance can also pinpoint refrigerant, ducting, or thermostat problems. And identifies if the system is likely to trigger a safety switch or is improperly sized.

HVAC maintenance gives homeowners peace of mind that the system is working. And at peak energy efficiency levels. After HVAC maintenance, the HVAC technician informs the homeowners. If the HVAC unit shows signs that raise concerns. And how to address those concerns.

When and how often should HVAC maintenance be done? (Hint: Yearly in the fall and spring)

We recommend HVAC maintenance at least once yearly to ensure the system works. But, other factors, such as how often the system runs? Where its located? And the type of system. All affect how frequently a system should have HVAC maintenance done.

An HVAC system in a dusty environment with lots of debris and poor indoor air quality will get dirty sooner. Depending on the type of HVAC system, it can have different energy sources. Such as gas heating or refrigerant cooling (electricity). If so, it should be checked at least twice a year. That way, each component can be inspected and maintained in its operating conditions.

The best time to get HVAC maintenance on an HVAC system is before the cooling or heating seasons. In the fall or spring. But, this isn't always easy to time. Because that is when everyone needs their HVAC system maintained. Which can result in less scheduling availability or higher prices. When scheduling HVAC maintenance, it is better to get it done earlier than later. That way, any concerns could be addressed and fixed on time so that the system works when needed.

Below we discuss what HVAC maintenance includes and the importance of each item.

What does HVAC maintenance include? (Preventative maintenance checklist)?

HVAC systems include components that enable the system to heat, ventilate, and cool. All HVAC units offer a form of filtration to protect the system. But depending on the type of HVAC system, the filter type, and other components. The maintenance may vary.

Below we discuss the various checkpoints and services HVAC maintenance includes.

Cooling System Maintenance

The cooling system (and heat for heat pumps) should be checked yearly. The cooling system has an outdoor unit. The outdoor unit is known as an air conditioning or heat pump system. It includes a coil, electronics, and a compressor. The outdoor unit gets paired with an indoor coil and an air handler. The air handler can be a gas furnace or an air handling unit.

The cooling systems checkpoints include electrical, refrigerant, and airflow metrics. These checkpoints determine if the system is working correctly. And if anything needs to be adjusted or serviced. Other visual and noise observations show any signs of wear and underlying problems.

The airflow metrics are unique to each system. And each HVAC system has its specifications for airflow requirements. The specifications are located on the HVAC equipment.

The electrical checkpoints include checking the capacitors. There are capacitors on the outdoor condenser and indoor air handling unit. These tests include checking the amp draws to the motors. The compressor motor, the outdoor fan motor, and the indoor fan motor. A check is done to ensure the proper voltage is received and distributed. To and from the transformers and throughout the control boards.

Ideal electrical readings are unique to each system and are listed on the HVAC unit. And each capacitor has a microfarad rating that the capacitor needs to meet. An electrical failure will prevent the air conditioning system from working.

A refrigerant pressure reading and a subcooling and superheat temperatures test is done. To verify that the refrigeration cycle works. Off readings can show a refrigerant leak or other problems with the HVAC system. Such as dirty indoor or outdoor coils, restricted filters, or ducting problems.

Each system has a pressure chart. The pressure chart indicates how much pressure the refrigerants should be under. The refrigerant pressure and required subcooling and superheat vary. And are different at each unit and outdoor temperature.

A static pressure test ensures the system gets proper airflow. Airflow is essential for the refrigeration cycle can happen. And the temperature difference is tested. The temperature is taken for the air going into the system and the air going out.

The maximum static pressure a system should have is stated on the air handling unit.

The system is also inspected for cleanliness. Signs of leakage or a clogged AC condensate drain line. And for excessive noise or vibrations.

Depending on the HVAC pro's findings, they may suggest an HVAC system cleaning. For the indoor or outdoor coil. A refrigerant leak test and repair. Ducting upgrades. Unclogging an AC drain line or replacing an electrical component.

Heating System Maintenance

The two most common heating systems are gas furnaces and heat pumps. You can learn more about the types of HVAC systems here. But for HVAC maintenance, heat pumps follow the same maintenance as cooling systems. The slight difference is that they have more electronics and a reversing valve.

Maintenance of a gas furnace includes checking and adjusting gas pressures. Ensuring proper combustion and exhaust of the flame and fumes. Ensuring that the safety switches are working correctly. And inspecting the system's motors and electrical components. High-efficiency furnaces produce moisture condensation. So drainage lines should be checked and cleared during maintenance to prevent leaks.

Gas pressure should be checked and adjusted yearly. That is because the gas supply pressure from the city could change. Which can affect the pressure making its way into the system.

A gas pressure that is too high can damage the burners. Or burn improperly, increasing the risk of carbon monoxide leakage. And causing the system to overheat. A system that overheats will shut off because of a triggered safety switch. And there is a risk of a cracked heat exchanger if it frequently gets too hot.

Inspecting the motors, electrical components, and safety switches ensure the inducer motor works. The inducer motor creates a good draft for the fumes to be exhausted through the FLUE vent pipe. A faulty inducer motor or a blocked FLUE vent pipe will signal the system that there is a problem, and it won't start. You can learn more about how a furnace works. But in short, an ignition and operation sequence ensures the system operates safely. This sequence consists of safety switches. If a safety switch doesn't pass, the ignition sequence won't continue.

The rest of the system electronics must be checked. And the flame sensor is cleaned. Failure to clean the flame sensor can cause the furnace not to work. The flame sensor is a safety precaution. If no flame is detected, the gas valve will shut off to prevent a gas leak in the home. During maintenance, an HVAC pro will also check the control board. And other electronics, such as capacitors and transformers. To ensure the system receives and distributes the power correctly.

A carbon monoxide leak test ensures the system works safely. If there is a carbon monoxide leak, it can indicate that the flames are not burning correctly. The fumes are not exhausting, or there is a crack in the heat exchanger.

Depending on the HVAC pros' findings, they may adjust the gas pressure. Clean the flame sensor. Clear out any blockage in the FLUE vent pipe or pressure switch tubing. Or clear any condensation blockage for high-efficiency furnaces. They may also suggest replacing a part. Such as a transformer, control board, capacitor, or safety switch that isn't good.

Ventilation system maintenance

Most homes don't have a ventilation system designed with an HVAC system. You can learn more about ventilation here. But in short, the goal of ventilation is to introduce outdoor air into the home. And improve indoor air quality.

When designed within an HVAC system, the home can have fresh air exchanges with the air outdoors. Depending on the ventilation system, maintenance could involve cleaning or replacing filters. Ensuring that the electronics communicate with the rest of the HVAC system. And that the mechanisms are working.

Homes also have kitchen and bathroom ventilation. These ventilation systems don't usually fall under HVAC maintenance. However, most HVAC pros understand bathroom and kitchen ventilation well. And could help if something is wrong with the kitchen or bathroom ventilation.

Ducting system maintenance

Ducting is a crucial component in a ducted HVAC system. And should be tested and inspected during each visit. The ducting can affect the HVAC unit's performance and indoor air quality.

A visual inspection of the ducting ensures they are connected and clean. Next, a static pressure test determines if there are restrictions within the system. Or if there is too little restriction in a system. A pro should always check static pressure with a clean filter. If there is a restriction in the system, it could be because of a dirty or restrictive filter. A restricted indoor coil or a sign of ducting problems.

Too little restriction can indicate disconnected ducting or ducting problems. If any ducting is disconnected, the HVAC pro may connect it on the spot or schedule a time to fix it. And if the ducts are dirty, they may suggest duct cleaning or replacement. You can learn more about our recommendations regarding ducting here.

A static pressure test shows whether the ducting system is working. Or if any adjustments need to be made. Such as adding or removing supply or return ducts. Or resizing the ducting to ensure the system receives proper airflow. Proper airflow is essential for the refrigeration cycle to work. It prevents a gas furnace from overheating. And allows the motors to work with minimum strain. Which can increase their lifespan and help the system run efficiently.

The HVAC pro may take this further. By checking that each grille (vent) receives good airflow volume and velocity. And suggest air balancing if needed.

Indoor air quality system maintenance

Each home has various indoor air quality (IAQ) solutions. The type of maintenance needed for each IAQ solution is different. Every HVAC system has an air filter. And some have other indoor air quality solutions. Such as UV purification, humidity control, ventilation, and reaction defense systems.

Below we will discuss what needs to be maintained for each system. We discussed ventilation maintenance in a previous section.

The air filter should be checked and replaced if needed. Remember that many of the tests done in the previous sections need to be done with a clean filter. This ensures accurate measurements when checking the HVAC system's performance.

If there is a UV purification system, the bulb should also be checked and replaced if necessary. Most manufacturers recommend the UV bulb be replaced every 1 to 2 years. For maximum effectiveness.

The HVAC pro should check the humidity control systems as well. If a humidifier is in place, it may have a humidifier pad. The humidifier pad should be replaced, and if it is a steam humidifier, it should be cleaned from any erosion. You can learn more about the types of humidifiers here.

Dehumidifiers extract moisture from the air via condensation. And should be checked to ensure the process is working. And that the drain lines are unclogged.

Reactive defense systems include ionizers and PCO devices. Ionizers are usually maintenance-free. And PCO devices may need a UV bulb and another component known as the catalyst that needs to be replaced yearly.

All systems should be checked to ensure they are wired and communicating correctly. And working in sync with the rest of the HVAC unit.

Most HVAC pros also include an indoor air quality scanning report. To check the IAQ in the home and see if current IAQ solutions are working. If anything seems off, the HVAC technician will recommend how to improve the IAQ in the home.

HVAC Maintenance costs

The maintenance costs for the heating and cooling system vary. It depends on where you are located and how comprehensive the maintenance service is. There are various checks and services in heating and cooling maintenance packages. But, to get an idea, many companies offer promotional lowballed $79 tune-ups to "get in the door." And then up-sell their services. However, comprehensive HVAC maintenance can easily cost upwards of $350.

HVAC Maintenance FAQs

Are HVAC maintenance plans worth it?

Whether HVAC maintenance plans are worth it, depends on how much it costs and how much you are getting. Comprehensive plans that include HVAC system cleanings, check-ups, and adjustments. They are typically more expensive. However, they result in more efficient HVAC systems that last longer. Always consult with an Air Pro. And explore your options before committing to an HVAC maintenance plan.

What is an HVAC maintenance plan?

What are some DIY HVAC maintenance tips?

What is done during HVAC maintenance?

Can AC maintenance improve indoor air quality?


HVAC maintenance is often overlooked as part of your yearly home maintenance checklist. But, an HVAC system has many moving parts. They work together like clockwork. To ensure your home is comfortable and that the indoor air quality is pristine.

We covered many topics, such as the importance of HVAC maintenance. And how it keeps your system working safely, efficiently, and when needed. We discussed when and how often HVAC maintenance is required. And outlined what HVAC maintenance includes. We also talked about recommendations. Or adjustments you could expect from your HVAC pro.

Now that we spend more time in our homes being comfortable in them is more important than ever. And scheduling HVAC maintenance is easy. The maintenance takes about 1-2 hours and requires about 10-15 minutes of your time. At the beginning, show the HVAC pro where the systems are. And in the end, for the HVAC pro to present their work, findings, and recommendations. All you have to do is be home while they do the job.

Connect with a pro to schedule HVAC maintenance. Or contact us and comment below if you have any questions.

bottom of page