Frequently Asked Questions

Most homeowners should plan to change (or clean, if reusable) their air conditioner/heat pump air filter about every 1–3 months during cooling season. A good rule of thumb is **every 30 days** if you have pets, allergies/asthma, a dusty home, or run the system frequently; **every 60–90 days** may be fine for lighter use with no pets. Higher-efficiency pleated filters (often 3–5" thick, used in some systems) can sometimes last **3–6 months**, but it’s still best to check them regularly. The simplest approach is to **inspect the filter monthly**. If it looks gray, loaded with dust, or you can’t see much light through it, replace it. A clogged filter restricts airflow, which can reduce comfort, raise energy bills, and contribute to issues like coil icing and unnecessary wear on the blower. Always install the correct **size** and follow the airflow arrow on the filter frame. If you’re not sure which filter type is best for your system (especially if you’re considering a higher MERV rating), or you’re changing filters often and suspect airflow or duct issues, we’re happy to help. Call **Mack Morris Heating & Air Conditioning** at **(434) 823-2665** for personalized recommendations for your Charlottesville/Central Virginia home.

Proper AC care starts with routine maintenance you can do at home. The most important step is changing or cleaning your air filter regularly (typically every 1–3 months, more often with pets, allergies, or heavy use). A clean filter improves airflow, helps your system cool efficiently, and reduces strain on the blower and compressor. Also keep supply/return vents inside your home open and unobstructed, and set your thermostat to a consistent, reasonable temperature to avoid excessive cycling and wear. Outside, keep the outdoor condenser unit clear. Remove leaves, grass clippings, and debris, and maintain at least 2 feet of clearance around the unit for proper airflow. Gently rinse the outdoor coil with a garden hose (light pressure) if it’s visibly dirty—avoid pressure washers, which can damage the fins. Make sure the unit stays level, and trim back shrubs or branches that can block airflow. If you notice ice on the refrigerant lines, unusual noises, weak airflow, or higher-than-normal utility bills, it’s best to shut the system off and have it checked to prevent bigger issues. Finally, schedule professional tune-ups—ideally once a year in the spring—so a technician can clean and inspect coils, verify refrigerant charge, check electrical components, confirm safe drainage, and ensure the system is operating at peak efficiency. If you’d like personalized guidance for your specific equipment and home, call Mack Morris Heating & Air Conditioning at 434-979-7129.

If your air conditioner is running constantly but not effectively cooling your home, there are several potential causes to consider. One common reason is a clogged or dirty air filter, which restricts airflow and reduces the system’s efficiency. Replacing or cleaning your air filter regularly, typically every 1 to 3 months, can often resolve this issue and improve cooling performance. Another possibility is that your AC unit is low on refrigerant due to a leak or improper charge. Refrigerant is essential for heat exchange, and without the right amount, the system can run continuously without adequately cooling. Additionally, issues like a malfunctioning thermostat, dirty condenser coils, or blocked vents can also contribute to poor cooling and constant run times. It’s important to ensure all components are clean, unobstructed, and functioning correctly to optimize performance. If you’ve checked basic maintenance items or notice symptoms like ice buildup on your unit or unusual noises, it’s best to contact a professional technician. At Mack Morris Heating & Air Conditioning, we’ve been serving Charlottesville and Central Virginia for over 40 years, helping homeowners diagnose and fix AC issues quickly and efficiently. Feel free to call us at 434-979-7129 for personalized assistance and to schedule a thorough system inspection.

During a heat wave, setting your air conditioner to an ideal temperature is important for both comfort and energy efficiency. The U.S. Department of Energy recommends setting your thermostat to around 78°F (25-26°C) when you are at home and awake. This temperature strikes a good balance between keeping your living space comfortable and minimizing energy consumption, helping to reduce your cooling costs during extreme heat. If you are away from home during the day, it’s advisable to raise the thermostat a few degrees higher, around 85°F (29-30°C), to avoid unnecessary energy use. When you return, lowering it back down to 78°F will quickly restore comfort. Using a programmable or smart thermostat can make these adjustments easier and more automatic, ensuring your system runs efficiently without sacrificing convenience. Remember, every home is different due to factors like insulation, sun exposure, and the efficiency of your HVAC system. If you’re unsure what temperature is most effective for your specific situation or want help optimizing your system for summer heat waves, feel free to call us at 434-979-7129. Our experienced technicians at Mack Morris Heating & Air Conditioning are happy to provide personalized advice and service to keep your home comfortable all season long.

Ice on your outside AC unit is a common issue that usually indicates a problem with your system’s airflow or refrigerant levels. When your air conditioner’s evaporator coil gets too cold, moisture in the air can freeze on it, causing ice to form. This can reduce the efficiency of your unit and, if left untreated, may lead to more serious damage. Several factors can cause your system to freeze up. Restricted airflow is a common culprit, which might be due to a dirty air filter, blocked vents, or issues with your blower fan. Low refrigerant levels caused by leaks can also lower the pressure in the system, leading to ice build-up. Additionally, outdoor temperatures below 60°F can sometimes cause freezing, especially if the unit is running for extended periods or is undersized for the cooling load. If you notice ice on your outside unit, it's best to turn off the system to prevent further damage and allow the ice to melt. Check and replace dirty air filters regularly and ensure that no vents or registers are blocked. Since diagnosing refrigerant leaks and other mechanical issues requires professional expertise, we recommend contacting a licensed HVAC technician. At Mack Morris Heating & Air Conditioning, we’ve been serving Charlottesville and Central Virginia for over 40 years and can help diagnose and fix the problem quickly. Feel free to call us at 434-979-7129 for personalized assistance and to schedule a service visit.

Yes, a dirty air filter can indeed cause your air conditioner (AC) to stop working properly, and in some cases, it may even cause the system to shut down entirely. Your AC’s air filter plays a crucial role in maintaining airflow and protecting the internal components from dust, dirt, and debris. When the filter becomes clogged, airflow is restricted, which can lead to reduced cooling efficiency, increased energy consumption, and strain on the system’s components. When airflow is limited by a dirty filter, the evaporator coil can freeze, causing your AC to blow warm air or stop blowing air altogether. Additionally, the system’s blower motor has to work harder to push air through the clogged filter, which can overheat the motor and trigger safety shut-offs to prevent damage. This not only affects your comfort but may also lead to costly repairs if the issue is not addressed promptly. To prevent these problems, it’s important to check your air filter regularly, generally every 1 to 3 months, and replace it as needed, especially during heavy usage periods in the summer. Using high-quality filters and maintaining a regular replacement schedule helps ensure your system runs efficiently and reliably. If you’re unsure about replacing your filter or if your AC still isn’t working after changing it, feel free to call us at 434-979-7129. Our experienced technicians at Mack Morris Heating & Air Conditioning are happy to provide personalized advice and service to keep your system running smoothly.

Setting your air conditioner to 60 degrees won’t cool your home any faster and may actually cause unnecessary wear on your system. Air conditioners are designed to cool your space at a steady, controlled pace. When you lower the thermostat to an extremely low temperature, the AC will run longer, trying to reach that setting, but it won’t speed up the cooling process because the unit cools at a fixed rate. Running your AC consistently at such a low temperature can also lead to higher energy bills and put added strain on your equipment. Instead, set your thermostat to a comfortable temperature, typically between 72 and 78 degrees in the summer, and allow your air conditioner to cycle as needed. Using a programmable thermostat can further optimize cooling efficiency by adjusting temperatures based on your schedule. If your AC is struggling to cool your home effectively, or if you want personalized advice on optimizing your system, feel free to give us a call at 434-979-7129. Our team at Mack Morris Heating & Air Conditioning is happy to help you keep your home comfortable and your system running efficiently.

Our IAQ testing uses the AirAdvice for Homes® M5200 to measure key factors that impact health, comfort, and safety—like particles, chemical pollutants (VOCs), CO₂, temperature, relative humidity, and carbon monoxide. You’ll receive a clear report (FlashReport or SmartIAQ), and we’ll explain what it means and which improvements make the biggest difference for your home. [Schedule an IAQ Test](https://mackmorrisheating.com/contact) [Find our more about indoor air quality](https://mackmorrisheating.com/services/indoor-air-quality)

An [air scrubber](https://mackmorrisheating.com/air-scrubber) is an indoor air quality device that’s installed in your home’s HVAC system to help clean the air as it circulates. Unlike a standard air filter that mainly captures particles passing through the return air, an air scrubber uses advanced technology (commonly UV light, catalytic processes, and/or ionization depending on the model) to reduce airborne contaminants throughout the system and living spaces. Many are designed to target things like odors, smoke/VOCs, mold spores, bacteria, and viruses, in addition to helping with dust and allergens. Air scrubbers can be a good option for households dealing with persistent odors, allergies/asthma triggers, pets, smoke exposure, or concerns about microbial growth, especially in humid Virginia summers when moisture can contribute to mold. They’re typically installed near the air handler or ductwork, work automatically when the system runs, and are often used alongside a properly sized high-quality filter for best results. Keep in mind that results depend on the specific product, your home’s airflow, humidity control, and overall ventilation. If you’re considering an air scrubber, it’s smart to have a professional evaluate your system, filter setup, duct condition, and humidity levels to make sure it’s the right solution (and properly matched to your equipment). For personalized recommendations for your home in Charlottesville or Central Virginia, call Mack Morris Heating & Air Conditioning at **434-979-7129**.

In winter in Virginia, a good general guideline is to set your thermostat back about **5–10°F lower than your normal “home” temperature** while you’re away. For many households, that ends up around **60–65°F** during daytime absences, depending on comfort needs, insulation, and your heating system. This helps reduce energy use without letting the home get so cold that the system has to work excessively hard to recover. If you’ll be gone **overnight or for multiple days**, it’s usually smart to keep the home at **no lower than 55–60°F**. That helps protect plumbing from freezing and reduces moisture-related issues. Also consider your specific situation—homes with older insulation, drafty areas, or rooms over crawlspaces may need a slightly higher setting, and households with pets or sensitive individuals may prefer less of a setback. A few practical tips: use a **programmable or smart thermostat** to automate set-backs and warm-ups, and make sure your system is maintained (clean filter, clear vents, and a tuned-up furnace/heat pump) so it can recover efficiently. If you’re uncertain what setback is best for your equipment—especially with heat pumps or dual-fuel systems—call **Mack Morris Heating & Air Conditioning at 434-979-7129** and we’ll help you choose settings that balance comfort, efficiency, and protection for your home.

We recommend servicing your HVAC system twice a year - once before heating season and once before cooling season. Regular maintenance helps prevent breakdowns and improves efficiency.