Why Your AC Runs Non-Stop When It Reaches Set Temperature


AC running constantly

While a constantly running air conditioner may be more reassuring than one that doesn’t run at all, it’s also a sign that a breakdown is on its way. If your AC is running non-stop even after reaching its target temperature, one or more conditions are prompting it to strain more than it should to cool your home.

Common Causes of an AC Running Constantly

Your air conditioning system works in cycles: it runs for about 15 minutes at a time until it reaches the appropriate temperature, turns off for about 10 minutes, and then turns on again. Problems with your system, however, can cause it to stay running for longer periods of time or indefinitely. Not only does a constantly running AC increase energy consumption and electricity bills, but it also indicates bigger underlying problems with your air conditioner that often lead to further damage and higher repair costs.

If your AC cooling cycles last more than 30 minutes or run all day, you likely have one of the following common AC problems:

  • Thermostat fault
  • Dirty or clogged air filter
  • Low refrigerant
  • Improperly sized AC unit
  • Poor airflow, blocked vents or registers
  • Inadequate insulation
  • Extreme temperatures
  • Dirty evaporator or condenser coils
  • Worn-out/old unit

Diagnosing and Fixing Issues with Your AC Unit

Use these strategies to help you identify issues and determine when to call a professional.

Check thermostat settings

The thermostat acts as the control and communication center for your entire HVAC system. Check the program settings on your thermostat—keep the temperature at a moderate level and ensure it is on cooling mode rather than just fan mode.

Even with correct settings, your thermostat may have other problems with its temperature sensors and be unable to communicate the room’s temperature accurately. Place a thermometer near the thermostat to see if it reads about the same temperature. If it displays temperatures differing by more than one or two degrees, your thermostat may need recalibration, new batteries, sensor replacement, or wiring repair.

Inspect and replace air filters

Dirt, pet dander, dust, and other debris can build up in your AC’s air filter, eventually clogging and restricting airflow throughout the system. With insufficient airflow, your AC system may struggle to efficiently cool and deliver conditioned air to all areas of your home. Dirty air filters can also cause other debris to enter the system and accumulate on other parts, such as the evaporator coils, which are also crucial for efficient cooling.

Air filters are usually between the return vent and air handler unit, possibly behind a panel. Remove the panel, and inspect the air filter — if it’s been longer than three months since replacement or has obvious buildup, replace it with a new filter that matches the model listed in your owner’s manual.

Inspect ductwork and vents

Even if your air filter is in pristine shape, blocked or damaged ductwork and vents can reduce airflow and efficiency. Inspect your ductwork for leaks, blockage, or other damage, either patching up minor damage yourself or scheduling a professional repair. An HVAC technician can also recommend and install insulation to minimize heat gain to conditioned air.

Ensure that furniture or other items don’t block the supply and return vents. Feel for airflow from the vents by holding a sheet of paper against them, investigating those that don’t blow or pull in air as they should. Keep the vent dampers fully open to maintain proper pressure in your AC system — closing or obstructing vents can cause pressure imbalances that strain and hinder the efficiency of your unit.

Look for signs of low refrigerant

Although only licensed HVAC technicians are qualified to work on your refrigerant line, you can still inspect it by referencing visual or auditory cues. Frost or ice buildup, hissing, or bubbling sounds often indicate refrigerant leaks and low charge. If you notice these issues, contact an HVAC technician to locate and repair the leak and recharge the system.

Request consultation with an HVAC technician

Depending on the size and layout of the building, each home requires a different AC unit to match its cooling power needs. If your AC is undersized to your home’s square-footage and lacks sufficient cooling power, it may not be capable of matching cooling needs with regular cycles; instead, it will run constantly to keep up. Some units also lose efficiency and power as they age and don’t provide the same performance they used to, eventually requiring replacement about every 20 years.

An HVAC technician can assess your existing AC system’s size and age to determine if repair or replacement is more cost-effective. If you need a replacement, your technician can use their assessment of your home and existing system to recommend and install a compatible unit.

Preventative Measures to Avoid AC Unit Running Non-Stop

In addition to the required repair, the following strategies can help ensure the efficiency and performance of your AC system.

Regular DIY maintenance

Routine AC maintenance can help keep its parts and components in good working shape and ensure the system’s performance during Amarillo’s sweltering heat. Between professional visits, try these DIY maintenance strategies:

  • Check and replace air filters
  • Hose branches, leaves, and other debris off the outdoor unit
  • Wipe dust off the inner AC unit
  • Inspect ductwork

Update thermostat technology

Modern thermostats come with upgraded technology that better regulates your home’s temperature. Programmable and smart thermostats provide precise control over temperature regulation, allowing you to set and change temperatures for specific days, hours, or even according to when it senses you leave or arrive home. They also may come with HVAC monitoring tools that alert you to system needs or provide maintenance reminders.

Insulation upgrades

Some ductwork requires insulation to prevent heat transfer and efficiency loss. Check the existing insulation, request professional repair as needed, or consult with a technician to customize an insulation solution.

Seal windows and doors

Seal leaks around your windows and doors with caulking and add weather stripping to keep cool air from escaping. Uncovered windows can also transfer heat into your home, especially when the sun is blazing in Amarillo. Keep blinds and curtains closed during peak hours of the day to minimize heat creeping in via solar gain. Consider upgrading to energy-efficient window coverings, which can reduce heat transfer by up to 60%.

Schedule professional maintenance

Schedule professional HVAC maintenance services once or twice a year—ideally once in the spring to get your AC summer-ready and again in the fall or at the end of the cooling season to address wear from the summer. With expert skills, knowledge, and experience, HVAC technicians can minimize repair needs, extend your unit’s lifespan, reduce energy consumption and bills, and ensure reliable cooling and comfort.

Keep Cool and Schedule AC Service with Amarillo Air Conditioning

Serving Amarillo, Canyon, and nearby Texas areas, our expert team at Amarillo Air Conditioning provides professional advice and peace of mind during cooling and heating seasons alike. Rely on us for AC maintenance, repair, and more — contact us today or book online.

Frequently Asked Questions

What temperature should I set my AC to?

The Department of Energy suggests setting your AC to around 70 degrees when you’re home and slightly increasing the temperature when you’re not home.

Should I set my AC cooler on startup?

When you turn on your AC, avoid setting it to a colder temperature than normal. Keep your AC at a consistent temperature to regulate the indoor climate and avoid unnecessary strain on your unit.

CONTACT Amarillo Air Conditioning, Inc.

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