Why Is My AC Not Cooling Below 75? The Reasons and Solutions You Must Know About!

It’s vital to have a well-functioning air conditioner in your home. But what if your AC is not cooling below 75 degrees Fahrenheit? This can be a massive concern. Especially if you live in a hot and humid climate, this problem can be frustrating and uncomfortable, even if you set the thermostat lower.

There are many possible reasons why your AC is not cooling below 75 degrees, such as dirty filters, low refrigerant levels, faulty thermostats, blocked vents, or malfunctioning compressors. You can solve some of these problems by yourself, while others can require professional assistance.

In this article, we will explain why your AC might not be cooling below 75 degrees and what you can do to fix it. We will help you identify your AC problem’s cause and provide tips and solutions to improve its performance and efficiency. Let’s dig into the detail below!

Why is My AC Not Cooling Below 75: The Reasons

If you’re wondering, ‘Why my AC temperature is not going down,’ or ‘Why is my AC not cooling below 75,’ it’s time to explore all the possible and relevant reasons for this problem. Let’s read about the reasons below and look at the possible signs for each reason to understand the problem better.

Dirty/Clogged Air Filter

The air filter in your AC system traps dust, dirt, pollen, and other airborne contaminants that can affect indoor air quality.

However, if the filter is not changed or cleaned regularly, it can become clogged and restrict the airflow through your AC system. This can cause your AC to work harder and longer to cool your home, resulting in higher energy consumption and lower cooling efficiency.

Signs and symptoms of a dirty/clogged air filter

• Reduced airflow from the vents
• Dusty or dirty air coming out of the vents
• Increased allergy or asthma symptoms
• Frequent cycling of your AC unit
• Overheating of your AC unit

AC Blocked Condenser

The condenser unit is the outdoor part of your AC system that releases the heat absorbed by the refrigerant from the indoor air. It consists of a fan, a coil, and a compressor. The fan blows air over the coil to help cool the refrigerant, and the compressor pumps the refrigerant back to the indoor unit.

If the condenser unit has dirt, debris, plants, or other obstructions, it can reduce its ability to dissipate heat and affect your AC performance.

Signs and symptoms of an AC-blocked condenser

• The reduced cooling capacity of your AC unit
• AC isn’t cooling to set the temperature
• Higher energy consumption and bills
• Shorter lifespan of your AC unit
• Frequent breakdowns or repairs

If you’re having trouble with your blocked AC condenser, you can clean it in 5 easy ways!

Refrigerant Leak

Refrigerant is the substance that circulates through your AC system and absorbs heat from the indoor air. It then releases the heat outside through the condenser unit.

If your AC has a refrigerant leak, it will not be able to cool the air effectively and can cause your AC to run longer and harder than usual. This can result in higher energy bills and damage to your AC components.

Signs and symptoms of a refrigerant leak

• Ice buildup on the evaporator coil or refrigerant lines
• Hissing or bubbling sounds from the AC unit
• Reduced airflow from the vents
• Warm air coming out of the vents
• Higher humidity levels in your home

An Undersized AC

The size of your AC unit depends on the cooling capacity, measured in tons or British thermal units (BTUs) per hour. The size of your AC unit should match your home’s cooling load, which depends on factors such as the size, layout, insulation, orientation, and location of your home.

If your AC unit is too small for your home, it will not be able to cool your home adequately and can run constantly without reaching the desired temperature.

Signs and symptoms of an undersized AC

• Inconsistent or uneven cooling across your home
• High indoor humidity levels
• AC won’t cool below 76
• Frequent cycling or short run times of your AC unit
• High energy consumption and bills
• Reduced lifespan of your AC unit

Leaky Ductwork

The ductwork is the system of pipes or tubes that carries the cooled air from your AC unit to the different rooms in your home. The ductwork should be well-sealed and insulated to prevent air leakage, heat gain, or loss.

However, the ductwork can develop cracks, holes, or gaps over time due to wear and tear, rodents, or poor installation. This can cause the cooled air to escape before reaching your rooms and reduce the cooling efficiency of your AC unit.

Signs and symptoms of a leaky ductwork

• Higher energy consumption and bills
• Reduced airflow from the vents
• Hot or cold spots in your home
• Dusty or dirty air coming out of the vents
• Increased noise from your AC unit

An Older AC

The average lifespan of an AC unit is about 15 to 20 years, depending on the unit’s type, model, usage, and maintenance. As your AC unit ages, it can lose efficiency and performance due to normal wear and tear, corrosion, or outdated technology.

It can also require more frequent repairs or replacements of its parts. An older AC unit can not cool your home as effectively as a newer one and can consume more energy.

Signs and symptoms of an AC getting older

• Reduced cooling capacity or output of your AC unit
• AC won’t go below 70
• Higher energy consumption and bills
• Frequent breakdowns or repairs of your AC unit
• Outdated or obsolete features or technology of your AC unit
• Increased noise or vibration from your AC unit

Weak or Dead Thermostat Batteries

The thermostat is the device that controls the temperature and operation of your AC unit. It communicates with your AC unit through a series of wires and signals. Most thermostats run on batteries that need to be replaced periodically.

If your thermostat batteries are weak or dead, they can not be able to send or receive the correct signals to your AC unit and can cause your AC unit to malfunction or not cool properly.

Signs and symptoms of weak or dead thermostat batteries

• No display or blank screen on your thermostat
• Incorrect temperature readings or settings on your thermostat
• No response or delayed response from your AC unit when you adjust the thermostat
• Inconsistent or erratic operation of your AC unit

Clogged Drain Line

The drain line is the pipe that carries the excess moisture or condensates from your AC unit to a drain pan or a drain outlet. The drain line can become clogged with dirt, algae, mold, or other debris over time, preventing the condensate from flowing out properly.

This can cause the condensate to back up and overflow into your AC unit or home, causing water damage or electrical issues. It can also trigger a safety switch that shuts off your AC unit to prevent further damage. You can clean AC drain line in detail for efficient AC performance.

Signs and symptoms of a clogged drain line

• Water leakage or pooling around your AC unit or in your home
• The musty or moldy smell from your AC unit or in your home. It’s best to clean the mold in your window AC
• Reduced cooling capacity or output of your AC unit
• No power or operation of your AC unit

Tripped Circuit Breaker

The circuit breaker is the device that protects your AC unit and your home from electrical overload or short circuits. It shuts off the power to your AC unit when it detects a surge or a fault in the electrical system.

If your circuit breaker trips, it means that your AC unit is drawing more power than it can handle or that there is a problem with the wiring or the components of your AC unit. This can cause your AC unit to stop working or not cool properly.

Signs and symptoms of a tripped circuit breaker

• No power or operation of your AC unit
• No display or blank screen on your thermostat
• A flipped switch or a popped button on your circuit breaker panel
• A burnt smell of smoke from your AC unit or your circuit breaker panel
• The air conditioner is blowing cool but not cold

Why is the Thermostat Not Reaching Temperature AC?

The thermostat might not attain the intended temperature due to improper calibration or installation. If the thermostat is not calibrated properly, it might not read the temperature accurately, resulting in inadequate cooling.

In addition, if the thermostat is in direct sunlight, breezes, or heat sources, it cannot accurately reflect the room’s actual temperature, resulting in the air conditioning system failing to attain the desired temperature.

A malfunctioning thermostat or defective wiring could be another potential cause. If the thermostat is malfunctioning or the wiring is faulty, it cannot send the correct signals to the air conditioning system, preventing it from adequately cooling the space.

How to Fix the ‘AC Not Cooling Below 75’ Problem?

Suppose your AC unit is not cooling below 75 degrees Fahrenheit. In that case, even when you set the thermostat lower, you can experience a common AC problem affecting your cooling comfort and efficiency.

In this section, we will show you how to fix the ‘AC not cooling below 75’ problem by following these simple steps:

·         Check and Replace Your Air Filter

One of the easiest and most effective ways to fix the ‘AC not cooling below 75’ problem is to check and replace your air filter. If the filter is not changed or cleaned regularly, it can become clogged and restrict the airflow through your AC system.

This can cause your AC to work harder and longer to cool your home, resulting in higher energy consumption and lower cooling efficiency. You should check and replace or clean your air filter at least once every month during the cooling season.

·         Check and Recharge Your Refrigerant Level

The low refrigerant level is another common cause of the ‘AC not cooling below 75’ problem. You should check and recharge your refrigerant level.

You can use a pressure gauge to measure the pressure of the refrigerant in your AC system and compare it with the recommended level for your AC model. If the pressure is too low, you have a refrigerant leak that needs to be repaired and recharged.

·         Check and Adjust Your Thermostat

Another simple way to fix the ‘AC not cooling below 75’ problem is to check and adjust your thermostat. If your thermostat is set too high, it can not signal your AC unit to cool enough.

If your thermostat is faulty or inaccurate, it can not send or receive the correct signals to your AC unit and can cause your AC unit to malfunction or not cool properly.

You should check and adjust your thermostat settings. Plus, you should set your thermostat to a comfortable temperature lower than the current indoor temperature.

You should also ensure your thermostat is on the correct mode (cooling) and fan speed (auto). You should also check your thermostat’s batteries and replace them if they are weak or dead.

·         Check and Clear Your Vents

Another easy way to fix the ‘AC not cooling below 75’ problem is to check and clear your vents. The vents are the openings that allow the cooled air from your AC unit to enter the different rooms in your home.

The vents should be open and unobstructed to allow proper airflow and distribution of cooled air throughout your home. However, if the vents are closed or blocked by furniture, curtains, rugs, or other objects, they can reduce your AC unit’s airflow and cooling efficiency.

Ensure that all the vents in your home are open and free of any obstructions. It would be best to clean the vents occasionally to remove any dust or dirt that can accumulate on them. You can use a vacuum cleaner or a damp cloth to clean the vents gently.

·         Check and Repair Your Compressor

A faulty compressor is another possible cause of the ‘AC not cooling below 75’ problem. If the compressor is damaged or worn out, it can not pump the refrigerant properly and can cause your AC unit not to cool enough.

You should check and repair your compressor. Plus, you can use a multimeter to test the electrical resistance of the compressor and see if it is working properly. You can also listen for any unusual noises or vibrations from the compressor that can indicate a problem.

·         Check and Seal Your Ductwork

Another common cause of the ‘AC not cooling below 75’ problem is leaky ductwork. Over time, the ductwork can develop cracks, holes, or gaps due to wear and tear, rodents, or poor installation. This can cause the cooled air to escape before reaching your rooms and reduce the cooling efficiency of your AC unit.

Check and seal your ductwork. You can use a smoke or pressure test to detect any leaks in your ductwork. If you find any leaks, seal them with mastic or metal tape and insulate them with duct wrap or spray foam.

·         Check and Replace Your AC Unit

The last resort to fix the ‘AC not cooling below 75’ problem is to check and replace your AC unit. As your AC unit ages, it can lose efficiency and performance due to normal wear and tear, corrosion, or outdated technology. It can also require more frequent repairs or replacements of its parts.

An older AC unit can not cool your home as effectively as a newer one and can consume more energy. Replace your AC unit with a newer and more efficient one when it reaches the end of its lifespan or when the repair costs exceed the replacement costs.

You can also consult a professional AC contractor before installing a new AC unit in your home. They can calculate load and recommend the best AC unit size for your home. A properly sized AC unit will provide optimal cooling comfort and efficiency for your home.

How Long Should It Take to Cool a House From 80 to 72?

It isn’t easy to provide an exact timeframe for chilling from 80 to 72 degrees, but a rough estimate would be between 1 and 3 hours.

The time required to chill a home from 80 to 72 degrees varies based on several variables, including the size of the home, its insulation levels, the ambient temperature, and the air conditioning system’s efficacy.

However, it is essential to note that achieving a specific temperature within a specified time frame is not guaranteed, and there are limitations to consider.

The scale of the home has a substantial impact on chilling time. A larger home with multiple rooms and floors will require longer to cool than a smaller home. The air conditioning system must evenly distribute chilly air throughout the room, and larger rooms can have a greater volume of air to cool, resulting in a longer chilling period.

The house’s insulation also affects its cooling efficiency. Proper insulation reduces heat transfer between the indoor and outdoor environments, allowing the air conditioner to chill the indoor air more effectively.

As there is less heat gain from the outside and less burden on the AC system, it can reduce the cooling time in a well-insulated home compared to an inadequately insulated home.

4 Tips to Maintain Smooth and Efficient AC Cooling for the Entire Summer

In summer, you rely on your AC unit the most to keep your home cool and comfortable. However, if you want your AC unit to perform smoothly and efficiently throughout the summer, you must take steps to maintain it properly.

Here are four tips to help you maintain smooth and efficient AC cooling for the entire summer:

Tip 1. Schedule a Professional Tune-Up

One of the best ways to ensure smooth and efficient AC cooling for the entire summer is to schedule a professional tune-up before the cooling season begins.

A professional AC technician will inspect, clean, and adjust your AC unit and its components and fix any issues or potential problems affecting its performance or efficiency. A professional tune-up will improve your AC unit’s lifespan, reliability, and safety.

Tip 2. Change or Clean Your Air Filter Regularly

Another important tip for maintaining smooth and efficient AC cooling for the entire summer is to change or clean your air filter regularly. You should check and change or clean your air filter at least once every month during the cooling season.

Use a high-efficiency particulate air (HEPA) filter that can capture more and smaller particles than a standard filter. A clean air filter will improve your AC performance, lower your energy bills, and

Tip 3. Keep Your Thermostat Settings Optimal

Another simple tip for maintaining smooth and efficient AC cooling for the entire summer is to optimize your thermostat settings. You should set your thermostat to a comfortable temperature lower than the current indoor temperature.

Ensure your thermostat is in the correct mode (cooling) and fan speed (auto). Avoid adjusting your thermostat frequently or drastically, as this can cause your AC unit to cycle on and off more often and waste energy.

Tip 4. Keep Your Outdoor Unit Clean and Clear

Another tip for maintaining smooth and efficient AC cooling for the entire summer is to keep your outdoor unit clean and clear. To keep your outdoor unit clean and clear, you should keep the area around your outdoor unit clean and clear of any objects that can block the airflow.

Trim any bushes or trees too close to the unit and remove any leaves or grass clippings that can accumulate on the coil or fan.

Final Words

If you stick to these guidelines, you can eliminate the ‘AC not cooling below 75’ problem. In addition, you can keep your air conditioner running smoothly and efficiently all summer by having a professional inspect it, frequently changing or cleaning the air filter, adjusting the thermostat as needed, etc.

You’ll enjoy better cooling comfort and air quality inside, decreased energy costs, and a longer life for your air conditioner. We hope you found the information presented here useful and enlightening. Feel free to call or email us whenever you have concerns or questions about your air conditioner.

Frequently Asked Questions on AC Not Cooling Below 75

Why is my AC set at 75 but reads 80?

The thermostat needs readjustments if the system still isn’t functioning properly. To verify this, place a thermometer near the thermostat and give it a tap. If the readout changes after waiting 15 minutes, you know the thermostat is malfunctioning. Take a mental note of the thermostat’s location as well.

Is 75 Ok for AC?

The ideal temperature for our homes is between 74 and 76 degrees Fahrenheit. So, 75 degrees is a good, secure temperature. This is, however, only required when at home.

Can AC cool below 70?

Putting the thermostat below 70 degrees will not make cooling any quicker and might cause damage. Realize that there is often a temperature differential of 20 degrees between the inside and exterior of a building.