Don’t Let Your AC Silently Quit on You
Why Is My AC Running but Not Cooling?
A bad air conditioner won’t necessarily make a lot of noise. Sometimes, it will just start blowing warm air. If your air conditioner is running but not cooling, it’s time to call a pro.
Your Air Conditioner Sounds Fine but Isn’t Cooling. Why?
On average, air conditioners in the Dallas-Fort Worth area run for up to 2,800 hours per year. That’s more than double the national average! As a result, local AC systems often wear out pretty quickly. For Frisco residents, those failures are usually marked by rattling, whining, buzzing, bubbling, or banging noises.
However, not all issues are audible. Often, the AC sounds fine but is not cooling. You might find other symptoms, like ice buildup, water leaks, or odd smells. Maybe you have some rooms that are not cooling, while others are fine. Silent AC problems are fairly common in North Dallas, so it’s important to know the signs.
What Makes the Sounds You Usually Hear?
Your air conditioner will always make a certain amount of noise. The average outdoor condenser will produce 70 to 80 dB(A) of noise during normal operation. Generally, that sound consists of whooshing, whirring, and soft hums.
Those sounds come from air moving through the system, the fan, and the electric motor. The relay switch may also produce a single click when the system starts up. These are all normal.
Why Normal Sounds Might Delay Needed AC Repairs
When your air conditioner makes all the usual sounds, it can be easy to ignore it. For example, picture a hot summer day in Frisco. Your air conditioner is humming away as usual. You feel the breeze coming from the vents. However, the temperature doesn’t seem to be changing much. No biggie, you think. It’s a hot day, after all. At least the AC is still running, right?
These are the factors that can mask serious issues with your air conditioner. Even though the system might be moving air, it may not be cooling that air or moving it efficiently. The underlying issues aren’t producing odd sounds, which makes them hard to catch. The end result is delayed repairs and more expensive issues later on.
Silent AC Problems in North Dallas
Silent AC problems are easy to miss without a routine AC inspection. Common silent AC problems include faulty compressors, low refrigerant, dirty coils, duct leaks, or thermostat malfunctions. In some cases, the system may even be the wrong size for your home.
Compressor Problems
The compressor’s job is to circulate refrigerant. In some cases, it might not produce enough pressure to move refrigerant through the system. In others, it might just fail to start, resulting in your AC blowing warm air.
AC compressor problems can be very expensive in Frisco, often exceeding $6,000 to replace. You’ll want to be sure it’s not something else first, like a clogged filter or a refrigerant leak.
Low Refrigerant
Low refrigerant levels are surprisingly common in Frisco. Your AC’s efficiency can be significantly reduced as the result of a low refrigerant charge. Sometimes, a leak will make gurgling noises, but often, the issue is silent. There are other low refrigerant symptoms to watch for, including weak cooling, frozen evaporator coils, and a sweet chemical smell.
Dirty Coils
A frozen evaporator coil could also result from dirt buildup. We see this frequently in North Dallas. During operation, dirt, grime, and debris may accumulate on the coils, reducing their efficiency. The system then has trouble moving air over the coils, leading to ice buildup. Other dirty evaporator coil symptoms include longer runtimes, uneven cooling, and poor airflow from the vents.
Leaking Ducts
Leaky ductwork and poor cooling also go hand in hand. In fact, research indicates that 20% to 30% of conditioned air in residential ductwork is lost to duct leaks. If you have poor airflow from the vents, you may have a leaking duct somewhere. Higher energy bills, excess dust, odd odors, and uneven cooling from room to room may also indicate a duct leak.
Thermostat Issues
A faulty thermostat can affect your air conditioner in many ways. Obviously, if the thermostat isn’t operating at all, neither will the system. However, an air conditioner that runs continuously or short cycles could also result from faulty thermostat signals. In some cases, the fix may be as simple as moving the thermostat or changing the settings, but sometimes bad wiring or dust buildup may be the issue.
The System Doesn’t Turn Off
Is your air conditioner running nonstop? Longer AC cycles are normal during extreme Frisco heat. But it’s not good if your system runs continuously without bringing your home close to the thermostat setting. One of the most common issues in this area is that the AC unit is too small for your house. If you have an undersized AC, symptoms include nonstop running, higher electric bills, and poorer performance on hotter days.
If it’s not a sizing issue, there may be a clogged AC filter causing poor cooling. Frozen coils, low refrigerant, and leaky ductwork may also be to blame. A certified AC technician will need to examine your system to be sure.
Your Ears Can’t Measure AC Performance
While odd noises can often indicate AC issues, they aren’t the only symptom to watch for.
Some signs include:
- A Dirty Air Filter: It’s always important to keep tabs on your system’s air filter. A dirty filter can stop your AC from cooling effectively, so changing it out should be your first step. Often, the issues we see in Frisco and Plano can be prevented by changing the filter regularly.
- Ice Buildup on Coils: Check the indoor evaporator coils and the outdoor condenser for ice buildup. It will look like frost caked onto the coils. This symptom may indicate a malfunctioning blower fan, blocked vents, or refrigerant problems.
- Odd Smells: A sweet chemical smell might mean you have a refrigerant leak, while musty smells indicate mold. If you notice a “dirty socks” smell, there’s likely bacteria growing somewhere in your system.
- Water Leaks: Is there condensation dripping from the coils? Is it pooling around your outdoor unit? It’s not just Frisco’s humidity. It’s a condensation issue. Often, this pairs with ice buildup, but your system could also have a duct leak, obstructed airflow, or a refrigerant issue.
- AC Blowing Hot Air: Check the temperature. If your home’s temperature is not dropping, you either have an airflow issue, a refrigerant leak, or a faulty compressor.
- Uneven Cooling: If your upstairs is hot with the AC running but the downstairs rooms are cool, you likely need your system serviced. It could be a duct leak, a dirty air filter, or a thermostat issue.
- Abnormal Cycling: If your AC runs continuously, it might be too small or have a restricted airflow. Another common problem is short cycling, which is when the unit turns on and off too often. Short cycling often results from oversized air conditioners, which is actually very common in Texas. A local professional can diagnose oversized AC problems for you.
- Weak Airflow: Pay attention to the amount of air coming out of your vents. If it seems feeble, there may be a clog. Resist the urge to close a vent or two to get more pressure out of the rest. Closed vents are a frequent cause of AC problems in Frisco.
Quiet Problems Still Need Professional Attention
Many air conditioning issues can be solved by checking the power, your thermostat settings, and the filter. Compressor malfunctions, refrigerant leaks, dirty coils, and ice buildup all involve complex mechanisms. Those take specific parts, tools, and training to address properly. A NATE-certified AC technician can help you take care of these problems safely.
Is Your AC Running but Not Cooling? Call a Professional!
Do you have cooling issues even though your AC sounds fine? There’s a good chance that you have a serious problem that needs to be addressed promptly. A certified HVAC professional can help diagnose the core issue and fix it properly.
If you’re stuck wondering why your AC is not keeping up with Frisco’s summer weather, call us. At Colony Air Conditioning & Heating, we have been fixing air conditioners for 49 years. We have the tools and training needed to determine whether your AC issue is the result of a bad compressor or an oversized unit. Call us at 972.591.0293 to schedule air conditioner repairs anywhere in North Dallas.
Frequently Asked Questions
Can an AC problem happen without any strange noises?
Sometimes, your AC sounds fine but is not cooling. We see it all the time in Frisco. An absence of strange noises doesn’t necessarily mean your air conditioner is in perfect working order. If you notice abnormally high electric bills or subpar cooling, you may have a problem even though the system sounds normal.
What quiet AC problems can prevent a home from cooling?
A bad compressor, a refrigerant leak, dirty coils, leaking ducts, clogged filters, and thermostat malfunctions can all result in your AC blowing warm air. These may not affect the sounds your system makes while running, so knowing what to check can help diagnose poor cooling.
Can a weak capacitor cause the fan to run without proper cooling?
A weak capacitor could result in a weaker fan, leading to heat building up inside the condenser unit and overheating the system. Depending on the system, it could prevent the compressor—the mechanism that circulates refrigerant—from running, even while the fan keeps blowing.
Can low refrigerant reduce cooling without making noise?
Low refrigerant levels don’t necessarily make noise. In fact, refrigerant leaks often happen without the homeowner noticing. Signs of AC refrigerant leaks include poor cooling, chemical smells, and ice buildup.
Can dirty coils affect cooling without changing how the AC sounds?
Yes. Dirty coils don’t necessarily affect your air conditioner’s noise output. They may result in ice buildup and poor cooling, though. Look for those signs if your system seems to be running without lowering your home’s temperature.
Can a thermostat problem make the AC seem like it is running normally?
Generally, no. The equipment could still run, of course, and if you don’t know what to look for, it could seem normal. However, a faulty thermostat will usually affect the system’s operation in some way. Usually, the AC will either run continuously, run a short cycle, or flat-out refuse to start.
Should I keep running an AC that sounds fine but is not cooling?
We don’t recommend it. If your air conditioner isn’t cooling, all it’s doing is pushing Frisco’s muggy summer air through your house. Your AC will just wear out trying to reach your thermostat’s set temperature (which it won’t ever do if it’s not lowering the temperature). We advise shutting it off to avoid wasting energy and putting unnecessary strain on the unit.
What should I check when my AC sounds normal but the house is getting warmer?
The first thing to check is the thermostat. If it’s at the right setting, check the air filter. Dirty air filters affect AC cooling capabilities tremendously. You can also check the coils for ice or excess condensation. Finally, pay attention to what you smell. Mold, chemical leaks, bacterial growth, and burnt components all have distinctive smells.