Attic AC Running But Outside AC Unit Is Not: 5 Common Causes

Navigating the realm of AC issues can often lead to a sense of confusion and frustration. With a multitude of potential causes, from clogged filters to thermostat issues, it’s easy to feel overwhelmed when your cooling system functions suboptimally.

In this article, we aim to take the mystery out of your AC woes, exploring the possible reasons behind your system’s glitches and offering strategies for identifying and resolving the issue.

5 common causes of a non-responsive outside AC unit

1. Low refrigerant levels

• Low refrigerant levels can cause the outside AC unit to become non-responsive.
• Refrigerant is responsible for absorbing heat from the indoor air and releasing it outside. If the refrigerant level is low, it can hinder the cooling process.
• Contact a licensed HVAC technician to check for leaks, repair them, and recharge the system with the appropriate refrigerant.

2. Faulty capacitor

• A faulty capacitor can prevent the outside AC unit from running.
• Capacitors provide a jolt of electricity to start the motors in the unit. If the capacitor is faulty, the motors may not receive enough power to start.
• Have a professional technician test the capacitors and replace any faulty ones if needed.

3. A tripped circuit breaker or blown fuse

• A tripped circuit breaker or blown fuse can cause the outside AC unit to stop working.
• The circuit breaker or fuse protects the unit from electrical overloads. If it trips or blows, it indicates an electrical issue.
• Locate the electrical panel in your home and check if the circuit breaker has tripped or if a fuse has blown. Reset the breaker or replace the fuse if necessary. If the issue persists, consult an electrician.

4. Contactor problems

• Contactor problems can result in an unresponsive outside AC unit.
• The contactor is an electrical component that controls the flow of electricity to the compressor and fan motors. If the contactor is worn out or damaged, it may prevent the unit from turning on.
• Consider hiring a professional to inspect and replace the contactor if needed.

5. Faulty thermostat

• A faulty thermostat can lead to an unresponsive outside AC unit.
• The thermostat sends signals to the AC unit to turn on or off based on temperature settings. If it malfunctions, it may not send the correct signals.
• Troubleshoot by checking if the thermostat is set to cooling mode with a set temperature below the current room temperature. Try replacing the batteries if applicable. If issues persist, consult a technician to inspect and potentially replace the thermostat.

Investigating a clogged air filter’s impact on the AC unit

A clogged air filter can have a significant impact on the AC unit’s performance and efficiency. When the air filter becomes clogged with dust, dirt, or debris, it restricts the airflow entering the system. As a result, the AC unit has to work harder to pull in air, leading to decreased airflow and reduced cooling capacity.

This increased strain on the system can cause various issues, such as reduced cooling efficiency, longer cooling cycles, increased energy consumption, and even potential damage to the compressor. A clogged air filter can lead to poor indoor air quality as it fails to effectively capture allergens and pollutants.

Regularly checking and replacing the air filter, typically every one to three months, depending on usage and filter type, is crucial to maintaining optimal AC performance and promoting clean and healthy indoor air.

Thermostat issues: How capacitor malfunction affect your AC

A malfunctioning capacitor can have adverse effects on your AC unit, particularly in relation to the thermostat. The capacitor is responsible for providing the initial jolt of electricity that starts the motors in the AC unit, including the compressor and fan motors. If the capacitor is faulty or weak, it may not be able to supply enough power to start these motors properly. As a result, the AC unit may struggle to reach the desired temperature set on the thermostat or fail to turn on at all. This can lead to issues such as inadequate cooling, longer cooling cycles, or even complete system failure. If you suspect a capacitor malfunction, it’s a good idea to have a professional technician test and replace the faulty capacitor to restore proper operation of your AC unit and make sure your thermostat can effectively control the cooling process.

Diagnosing a refrigerant leak and its effects on cooling

• Inadequate cooling: A refrigerant leak can result in insufficient cooling performance from your AC unit. As refrigerant is responsible for absorbing heat from indoor air, a leak reduces the amount of refrigerant available to extract heat, leading to reduced cooling capacity.
• Longer cooling cycles: When there is a refrigerant leak, the AC unit has to work harder and for longer periods to achieve the desired temperature. This can result in extended cooling cycles as the system struggles to compensate for the reduced refrigerant levels.
• Poor airflow: A refrigerant leak can cause ice to form on the evaporator coil, restricting airflow. Reduced airflow means that less air is being cooled and distributed throughout your space, resulting in decreased comfort and inefficient cooling.
• Increased energy consumption: As the AC unit compensates for the refrigerant leak by running longer and working harder, it consumes more energy. This can lead to higher utility bills and unnecessary energy expenditures.
• Compressor damage: Low refrigerant levels due to a leak can cause the compressor to overheat and potentially sustain damage. The compressor is a vital component of the AC system, and if it becomes damaged, it can lead to expensive repairs or even require a complete replacement.

The circuit breaker tripped. Understanding AC electrical issues

The circuit breaker is designed to protect the AC unit from electrical overloads, which can occur due to various reasons such as a short circuit or excessive current draw. When the circuit breaker trips, it cuts off power to the AC unit, preventing further damage. To resolve this issue, start by locating the electrical panel in your home and identifying the tripped breaker.

Resetting the breaker by flipping it back to the “ON” position may solve the problem if it was simply a temporary overload. However, if the circuit breaker repeatedly trips, it could indicate a more serious underlying issue, such as a faulty component in the AC unit or a wiring problem. In such cases, it’s best to consult an electrician or HVAC technician to inspect and diagnose the problem accurately.

They can identify the root cause of the tripping and perform any necessary repairs or replacements to maintain the the safe and reliable operation of your AC unit. Remember, tampering with electrical components without proper knowledge can be dangerous, so it’s best to rely on professional assistance for resolving circuit breaker issues related to your AC system.

Dealing with leaky ducts: When chilled air goes astray

Leaky ducts can cause chilled air to go astray, resulting in reduced cooling efficiency and comfort in your home. When ducts have leaks or gaps, the cooled air intended for specific rooms or areas can escape into unconditioned spaces like attics, basements, or crawl spaces. This leads to wasted energy and uneven cooling throughout your home.

Leaky ducts can also allow unfiltered air to enter the system, potentially compromising indoor air quality. To deal with leaky ducts, it is recommended to have a professional HVAC technician perform a thorough inspection to identify the leaks and assess the overall condition of the ductwork. They may use techniques such as pressure testing or thermal imaging to locate and quantify the extent of the leaks.

Once identified, the technician can seal the leaks using appropriate materials like mastic sealant or metal tape. They may recommend insulating the ducts to further improve energy efficiency. Properly sealed and insulated ductwork can help make sure the cooled air reaches its intended destinations, optimizing cooling performance and enhancing overall comfort in your home.

Blocked condenser: Recognizing dirty coil issues in the AC unit

Over time, dirt, debris, and other contaminants can accumulate on the coil, forming a layer that inhibits heat transfer. This leads to reduced cooling efficiency, longer cooling cycles, and increased energy consumption. To recognize dirty coil issues, look for signs such as inadequate cooling, reduced airflow, or ice formation on the outdoor unit.

You may also notice higher energy bills or the AC unit struggling to maintain the desired temperature. If you suspect a dirty condenser coil, contact a professional HVAC technician. They can thoroughly clean the coil using specialized tools and cleaning solutions, restoring proper heat transfer and optimizing the performance of your AC unit.

Regular maintenance, including cleaning the condenser coil, can help prevent dirty coil issues and promote efficient cooling operation throughout the hot summer months.

The importance of clean coils for proper airflow

Clean coils are essential for maintaining proper airflow in your HVAC system. Whether it’s the evaporator coil located inside the indoor unit or the condenser coil in the outdoor unit, both are important for heat transfer and overall system performance.

Over time, these coils can accumulate dirt, dust, and debris, which restricts airflow and hampers the efficiency of the system. When the coils are dirty, the HVAC system has to work harder to maintain the desired temperature, leading to increased energy consumption and reduced cooling or heating capacity. Restricted airflow can cause inadequate temperature regulation, uneven cooling or heating, and even potential damage to the system.

By keeping the coils clean, you ensure that air can freely flow through the system, allowing for efficient heat exchange and optimal performance. Regular maintenance, including coil cleaning, is recommended to prevent airflow issues and keep your HVAC system running smoothly and efficiently.

Tips for maintaining your AC system and avoiding common issues

• Regular filter cleaning and replacement: Clean or replace your air filters regularly to maintain proper airflow and prevent dirt and debris buildup, which can lead to reduced cooling efficiency and strain on the system.
• Annual professional maintenance: Schedule annual maintenance with a professional HVAC technician to inspect and tune up your AC system. This helps identify and address potential issues before they become major problems, ensuring optimal performance and extending the lifespan of your unit.
• Keep outdoor unit clear: Regularly clear any debris, leaves, or vegetation around the outdoor unit to maintain proper airflow and prevent obstruction of the condenser coil. This helps optimize cooling efficiency and prevent overheating.
• Check and clean the condensate drain line. Make sure the condensate drain line is clear and free from clogs to prevent water backup and potential water damage. Regularly flush the drain line with a mixture of water and vinegar to remove any buildup.
• Adjust thermostat settings: Set your thermostat at a comfortable temperature and avoid extreme temperature fluctuations. Using programmable or smart thermostats can help optimize energy usage by adjusting settings based on your schedule.
• Avoid blocking vents: Make sure that no furniture, drapes, or other objects are blocking vents or registers. Blocked vents restrict airflow and can lead to inefficient cooling or heating.
• Monitor refrigerant levels: If you notice a decline in cooling performance, have a professional technician check the refrigerant levels and ensure there are no leaks. Proper refrigerant levels are essential for efficient cooling.
• Keep ducts sealed and insulated. Inspect and seal any leaks in your ductwork to minimize energy loss and allow for proper airflow. Consider insulating ducts in unconditioned spaces to improve energy efficiency.
• Clean evaporator and condenser coils: Regularly clean the evaporator and condenser coils to remove dirt, dust, and debris that can reduce cooling efficiency. Consult a professional technician for proper cleaning methods.