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When Texas Heat Meets AC Troubles

An AC not cooling is one of the most frustrating problems for a Longview homeowner, especially when Texas temperatures soar. It’s a common nightmare: you come home expecting cool relief, but the AC blows warm air, leaving your home uncomfortable no matter how long it runs.

Quick AC Not Cooling Diagnosis:

1. Check thermostat – Set to “cool” mode, temperature lower than room temp
2. Replace dirty air filter – Clogged filters restrict airflow and cooling
3. Verify power – Check circuit breakers and ensure outdoor unit has power
4. Clear outdoor unit – Remove debris from condenser coils and fan area
5. Listen for problems – Strange noises, hissing sounds, or lack of compressor operation
6. Look for ice – Frozen coils indicate refrigerant or airflow issues

In East Texas, with over 220 days of sunshine and temperatures often above 80°F, a working AC is essential for health and safety. Since over three-quarters of all homes in the US have air conditioners, system failures are a widespread concern.

Your AC relies on a careful balance of airflow, pressure, and temperature. When this is disrupted, your comfort suffers. Understanding the cause helps you determine whether it’s a quick DIY fix or time to call the professionals.

First Response: Simple DIY Checks for a Warm AC

When your AC isn’t cooling, don’t panic. Often, the problem can be solved with a few minutes of basic troubleshooting. Let’s cover the simple fixes that can restore your cool air without costing you anything.

Troubleshooting an AC Not Cooling Due to Thermostat Errors

Your thermostat controls your entire cooling system. Before assuming the worst, check if it’s working correctly. First, check if your thermostat is set to “cool” mode. It’s a common mistake to accidentally switch it to “fan only” or “heat.” Make sure the temperature setting is at least 3-5 degrees below the current room temperature to signal the AC to turn on.

Dead batteries can cause a blank display or erratic readings. Try replacing them if your thermostat is unresponsive. For smart thermostats, a simple power cycle (disconnecting from power for a few minutes) can resolve glitches.

Thermostat location matters. If it’s in direct sunlight or near a heat-producing lamp, it will get false hot readings. A drafty location can also prevent it from sensing the room’s actual temperature, hindering proper cooling. That switching to an Energy Star smart thermostat can reduce your heating and cooling bills by 8% by learning your habits and adjusting automatically.

The Critical Role of the Air Filter

If the thermostat is fine, check the air filter. A clogged air filter is the most common reason for an AC not cooling and is an easy fix. When the filter is packed with dust and pet dander, airflow gets restricted. Less air moving over the cold evaporator coils means less cooling power for your house.

A dirty filter also makes your system work harder, increasing your electric bill and risking expensive repairs. In extreme cases, restricted airflow can cause your evaporator coils to freeze solid.

How often should you change your filter? A general rule is every 1-3 months. If you have pets or live in a dusty area, change it monthly. A simple test is to hold the filter up to a light; if you can’t see through it, it’s time for a new one.

When installing a new filter, ensure the arrow on the frame points toward the furnace or air handler. Writing the installation date on the frame is a helpful reminder.

Checking Power and Airflow

Sometimes the solution is simple. Before diving into complex diagnostics, check these basics.

Circuit breakers can trip when the AC draws too much power on hot Texas days. Go to your electrical panel and look for any tripped breakers. Flip the breaker fully off, then back on. If it trips again immediately, you have a larger electrical problem that needs a professional.

Older systems may have blown fuses that need replacing. Always turn off power to the unit before checking or replacing fuses.

Blocked vents and registers can kill airflow to a room. Walk through your home and ensure all supply vents are open and not obstructed by furniture or curtains. Also, clean any dust or debris from the register covers to ensure clear airflow.

To test airflow, hold a tissue near each vent. Weak flow could indicate a blockage in the ductwork or a problem with the blower motor. If these checks don’t solve the problem, it’s time to investigate more complex issues.

Investigating Deeper System Problems

If simple fixes don’t work, the AC not cooling issue is likely more serious and located in your system’s core components. These problems usually require a professional, but understanding them helps you make informed decisions.

When an AC Not Cooling Points to a Refrigerant Leak

Refrigerant is the lifeblood of your AC, absorbing heat from inside your home and releasing it outside. Your AC is a closed-loop system, so low refrigerant means there’s a leak. This prevents your AC from cooling effectively and won’t resolve on its own.

Signs of a leak include:

• Reduced cooling power: The system runs, but the air from vents is lukewarm.
• Hissing or bubbling sounds: The sound of refrigerant escaping from the lines.
• Oily residue: Refrigerant contains oil that leaves greasy spots near a leak.
• Frozen evaporator coils: Low refrigerant changes system pressure, causing ice to form.
• Spiking energy bills: The AC works overtime to compensate for the lack of refrigerant.

Refrigerant leaks are also a safety concern. Refrigerant can contain toxic and flammable chemicals and should only be handled by licensed HVAC professionals who can safely locate and repair leaks, then recharge the system.

Frozen Evaporator Coils

Finding ice on your indoor unit is a clear sign of trouble. Frozen evaporator coils are a common symptom when an AC not cooling, but they are caused by an underlying issue, not the root cause.

The main causes are poor airflow (from a dirty filter or blocked vents) and low refrigerant levels. Dirty coils can also contribute to freezing by failing to absorb heat properly.

Symptoms include visible ice on the indoor unit or refrigerant lines, warm or no air from vents, reduced airflow, and water leaks near the indoor unit as ice melts.

If you see ice, turn off your AC immediately to prevent compressor damage. Set the thermostat to “fan only” to help circulate air and melt the ice, which can take up to 24 hours. Once thawed, check your air filter. If the problem returns, you likely have a refrigerant leak or another issue requiring professional service.

Outdoor Condenser and Compressor Faults

Your outdoor condenser unit releases heat from your home. When it fails, your AC not cooling is inevitable.

• Dirty Condenser Coils: These coils can’t release heat effectively when caked with dirt, grass, and pollen. Your system will overheat and struggle to cool. You can prevent this by gently hosing the unit down and keeping the surrounding area clear of debris.
• Fan Problems: If the large fan on top of your outdoor unit stops spinning, heat builds up quickly. If it’s not blocked by debris, the fan motor or capacitor may have failed.
• Compressor Failure: This is the most serious outdoor unit problem. The compressor is the heart of your AC; if it fails, cooling stops completely. Signs of trouble include grinding or screeching noises, excessive vibration, or the outdoor fan running while indoor vents blow warm air. A compressor that frequently trips the circuit breaker is another red flag.
• Electrical Control Problems: Failed capacitors or contactors can cause the unit to turn on and off rapidly or shut down entirely.

Because outdoor units involve high voltage and expensive parts, these problems require professional diagnosis and repair.

The Unseen Culprits: Maintenance, Sizing, and Ductwork

Sometimes, an AC not cooling problem isn’t from a sudden breakdown but from hidden issues that develop over time. Improper maintenance, incorrect system sizing, and ductwork problems can all quietly sabotage your home’s cooling performance.

How Lack of Maintenance Impacts Cooling

Regular maintenance is crucial for your AC’s health and performance. We recommend preventative tune-ups twice a year to catch small problems before they become expensive emergencies.

A common maintenance issue is a clogged drain line. Your AC dehumidifies the air, and this water must drain away. If the line clogs with algae or debris, a safety switch shuts down the compressor to prevent water damage, which stops all cooling. You may also notice higher humidity in your home.

Regular maintenance ensures your system runs efficiently, which lowers utility bills and prevents premature wear and tear. A properly serviced AC can last 15-20 years, while a neglected one may fail in as little as 8-10 years.

The Impact of Improper Sizing and Leaky Ducts

Even a perfectly working AC can fail to cool your home if it’s the wrong size or if your ducts are leaky. AC sizing must be precisely matched to your home’s needs.

• An oversized unit cools too quickly, failing to remove humidity. This leads to short cycling (frequent on/off cycles), which stresses the compressor and shortens its lifespan, leaving your home feeling cool but clammy.
• An undersized unit will run constantly on hot days but will never reach the set temperature. This wastes energy and causes excessive wear on the system.

Leaky ductwork is an invisible problem where cooled air escapes through holes or cracks in your ducts, often in the attic, before it reaches your rooms. This wastes energy and significantly reduces comfort. Poor insulation around ducts can also allow cool air to warm up as it travels through hot spaces.

Sizing and ductwork issues require professional assessment. Fixing them can dramatically improve your comfort and reduce energy bills.

Frequently Asked Questions about AC Cooling Issues

Dealing with an AC not cooling is a common frustration for Longview homeowners, especially during our hot East Texas summers. Here are answers to some frequent questions.

Why is my AC running but not blowing cold air?

It’s maddening when your AC runs but doesn’t blow cold air. This usually means a problem with the refrigeration cycle. The top three causes are:

1. Low Refrigerant: The system lacks the necessary chemical to absorb and move heat.
2. Dirty Condenser Coil: The outdoor unit is clogged with dirt and can’t release trapped heat.
3. Compressor Problems: The heart of your AC has failed and can no longer pump refrigerant.

In each case, the indoor fan may still run, but the air it circulates won’t be cool. A NATE-certified technician can pinpoint the exact cause.

Should I turn my AC off if it’s not cooling?

Yes, turn it off immediately. Running a malfunctioning AC can cause more extensive and expensive damage. Continuing to operate the unit can cause the evaporator coils to freeze solid, which can lead to permanent compressor damage—turning a simple fix into a costly replacement. You’re also wasting electricity. Turn the system off at the thermostat and call for service.

How can I make my AC cool better without a repair?

While some issues require a professional, you can take these steps to improve your AC’s performance and your comfort:

• Change the air filter. A clean filter restores proper airflow and can provide immediate improvement.
• Clean the outdoor unit. Clear away leaves and debris from around the unit. Gently rinse the condenser coils with a garden hose to remove dirt.
• Block sunlight. Close blinds and curtains during the hottest parts of the day, especially on south and west-facing windows.
• Check your vents. Ensure all supply and return vents are open and unblocked by furniture or rugs.
• Use the “auto” fan setting. This prevents the fan from circulating warm air when the cooling cycle is off.
• Minimize indoor heat. Avoid using the oven, clothes dryer, or dishwasher during peak afternoon heat.

These steps won’t fix a broken part, but they can help your system work more efficiently while you wait for professional help.

Get Your Cool Back with Professional Help

We’ve covered everything from simple DIY checks to complex system failures to help you understand why your AC not cooling. Changing an air filter or checking the thermostat are safe DIY fixes that often solve the problem.

However, issues like refrigerant leaks, electrical faults, and compressor problems are dangerous and require a professional with specialized training and equipment. Attempting these repairs yourself can lead to injury or turn a manageable repair into a complete system replacement.

If you’ve tried the basic troubleshooting steps and your AC still isn’t cooling, it’s time to call in the experts.

During a sweltering East Texas summer, you need expert help. Alco Air’s NATE-certified team has over 30 years of experience keeping Longview families cool. We’ve seen and fixed every cooling problem imaginable, and we know how to do it right the first time.

Our commitment to your satisfaction is reflected in our 4.8-star Google rating and our 100% money-back guarantee. If you’re not happy, we’ll make it right or refund your money. For homeowners who want to stay ahead of problems, our VIP Club offers premium care with priority scheduling and exclusive benefits.

Don’t spend another day sweating in your own home. When you need reliable AC repair in Longview, our team is ready to help. We’ll diagnose your AC not cooling problem quickly and restore your comfort, no matter how hot it gets outside.