Every San Marcos home needs a reliable cooling system. With functional air conditioning, it’s possible to effectively regulate indoor temperatures, humidity, and air quality on some of the hottest and most dangerous days of the year. But what happens when an air conditioner stops cooling effectively? Although your AC system might turn on, it may not have the ability to create a cool, comfortable, and ultimately safe indoor space that everyone can enjoy. Here are seven common reasons why air conditioners stop cooling, along with tips for troubleshooting these issues.

1. Your Air Conditioner Has Reached the End of Its Lifespan

The first and most important factor to consider when your AC system stops consistently producing cool air is its age. Older, more outdated equipment becomes increasingly less effective as the years wear on. Most air conditioners are designed to last for a maximum of 15 years. Even when this equipment is incredibly well-maintained, decreasing effectiveness is an unavoidable development. Well-maintained units may continue turning on for years beyond their expected lifespans, but this doesn’t mean that they’re capable of cooling, moderating humidity, or improving air quality in any efficient or sustainable way. If your air conditioner is 10 years or older, and if your AC repair bills or your home energy bills are steadily rising, it’s probably time for a replacement.

2. Your Air Conditioner Has Dirty Cooling Coils

If your AC system is relatively new, then the most likely culprit for poor performance is substandard coil maintenance. At the indoor compressor unit, your air conditioner has cooling coils that exist to absorb heat from the indoor air. When dirt accumulates on them, transferring heat between these coils and the air that gets blown across them becomes significantly harder for the unit to do. This decreases the air conditioner’s ability to extract warm air from the building interior. It also means that the air being released from the vents or air registers throughout the home will be significantly warmer than it should be. Scheduling professional maintenance will ensure that these components and all others are thoroughly cleaned and returned to their normal states of functioning.

3. Low Refrigerant Levels

Contrary to popular thought, air conditioners don’t magically produce cold air. Instead, they remove hot air from the building interior and release it outside. The refrigerant in your air conditioner is responsible for transferring heat outdoors to the AC condenser. If there’s a refrigerant leak, the system will become increasingly less effective at moving heat. Even though it will continue to run and use energy, indoor temperatures will largely remain unchanged. If you have a relatively new AC system, professional repairs should resolve this problem. However, if you have a very old air conditioner that still runs on R-22 refrigerant, upgrading your cooling equipment is definitely the best choice.

4. Debris Is Blocking the Outside Condenser Unit

The large, outdoor component of your AC system is its condenser unit. Condensers are usually housed in protective enclosures. However, this does not mean that they can’t be blocked by items that are haphazardly left nearby or by fast-growing shrubs, weeds, or other natural landscaping features. If this unit is obstructed in any way, heat that’s meant to be released from the condenser coils will be trapped. This disrupts the constant flow of heat removal from the home, slows down indoor cooling, and sets the stage for serious problems with overheating at the condenser. Fortunately, this issue often has a very quick and simple fix. Clean up scattered items by your condenser, and trim or remove any shrubbery or other foliage that’s encroached upon it. Always try to maintain at least 1 foot of total clearance between your condenser and any other items and as much as 18 inches when possible.

5. It’s Time for a Filter Change

When air filters get dirty, both air conditioner efficiency and indoor air quality (IAQ) can decline. This component should be changed once every one to three months, depending upon the recommendations of your HVAC service provider and your owner’s manual. During the summer, when the air conditioner is likely being used all day, every day, you probably shouldn’t wait more than 30 days to swap filters out. The more debris that accumulates on your air filter, the harder your system will have to work to create the desired temperature indoors. If your current filter choice is consistently underperforming, consider investing in one with a higher rating.

All AC air filters have a MERV rating that ranges between one and 16 and that denotes their efficacies in picking up increasingly smaller-sized particles. The more highly rated a filter is, the more particulates it can remove, and the better an AC system is likely to perform. For general use, try to get filters that are rated between 8 and 10. For days with smoke advisories or other air quality alerts, install filters with ratings of 11 or higher.

6. You Haven’t Set the Thermostat Correctly

Although the thermostat is often seen as a minor component, the thermostat is really the brains of the entire cooling operation. This unit dictates everything that the air conditioner does by telling it when to run and when to turn off. Understanding how your thermostat works and how to set it properly is essential. This is especially true for homeowners who’ve recently upgraded to smart, programmable units that have a learning curve.

In general, however, even very basic thermostats can cause some confusion. Simply turning these units to the “on” position, doesn’t necessarily mean that the cooling cycle is engaged. When set to “on” at the thermostat, central air conditioners will turn on and blow air, but the air the registers emit won’t be cooled. Check to ensure that your thermostat has been toggled to either “cool” mode. Central air conditioners will only kick into action when the thermostat setting is at this setting. If your AC system isn’t turning on at all, it may be time for a new thermostat or for thermostat repairs.

7. There Are Problems at the AC Compressor

Refrigerant is basically the lifeblood of your home cooling system. The indoor compressor and various other components act as the heart of this equipment and its arteries. The compressor ensures that the refrigerant is optimally pressurized and that it’s flowing like it should. Without a properly functioning compressor, the air conditioner won’t be able to absorb heat from the indoor environment. When cooling abilities greatly decline and all other possible causes have been checked, the source of the problem may lie at the compressor. With this issue, it’s always best to call a licensed HVAC contractor right away. Continuing to run the unit before the problem is resolved could result in progressive damages and, eventually, outright system failure.

At Oak Island Heating and Air Conditioning, we’re proficient in handling all types of air conditioner repairs. We offer reliable heating and cooling services in San Marcos and the surrounding areas. We also provide heat pump and indoor air quality services and an expansive selection of cutting-edge HVAC products. Call us today to have your air conditioner inspected, maintained, repaired, or replaced.

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