A reliable air conditioner is a homeowner’s best friend. But, when your AC unit is running nonstop, it can be discomforting. The temperature indoors becomes too cool for comfort and your utility bills surge higher due to the electrical power wasted by your system.

When your air conditioner won’t turn off, it could be linked to a variety of malfunctioning components – a clogged air filter, a frozen evaporator coil, a bad thermostat, debris on the condenser coils, a faulty switch, or other problems in your HVAC system.

So, what can you do to get it working properly again? In this article, Classic Heating and Air offers a few DIY tips to troubleshoot your system. When it keeps on running despite your best efforts, call our team for professional service.

Humidifier Work

Let’s start by understanding the reasons why your AC won’t turn off.

Introduction: Reasons Why Your AC won’t turn off

If your air conditioner won’t turn off, here are some common issues that may be present in your HVAC unit.

  1. Malfunctioning Thermostat

    Your thermostat acts as the commander of your HVAC system, telling it when to start and stop cooling your home.

    It usually has a lifespan of 10 years. As time goes by, a thermostat loses accuracy and experiences damages that disrupt its flow with the cooling system. Dust and dirt build-up on temperature sensors, making it difficult for the thermostat to detect the temperature of the room.

    Also, damage to the electrical wiring and loose wiring connections can disrupt signals sent from the thermostat to the air conditioner, causing it to run longer than necessary.

  2. Incorrect Thermostat Settings

    If your thermostat is set too low or programmed incorrectly, it may cause your AC unit to continuously run even when the desired temperature has been reached.

    Most of us keep our homes at a preferred set temperature. If someone adjusts the set temperature downward, your air conditioner will run for a longer period and won’t turn off when you expect it to.

    If your fan is in ON mode instead of AUTO, it constantly runs. Usually, a blower fan only runs during a cooling cycle to circulate cool air around the home. When the fan is left on at all hours of the day, you will hear the sound of your indoor component running and feel hot air blowing from your vents because the air conditioner isn’t on to produce cool air.

  3. Clogged Air Filter

    When an air filter is completely clogged with pollutants, it restricts airflow. The air conditioner has to work twice as hard to circulate air for cooling. This leads to continuous operation and potential damage to the system.

  4. Refrigerant Issues

    Air conditioners are designed with specific refrigerant volumes to ensure heat transfer through the cooling system. If leaks in refrigerant lines, damaged coils, or a defective expansion valve allow refrigerant to escape the system, it causes low refrigerant levels. The AC unit is unable to absorb and transfer enough heat. The system will run for hours on end as it attempts to bring the indoor temperature down to make up for this shortcoming.

  5. Incorrect System Sizing

    Air conditioners are designed with specific refrigerant volumes to ensure heat transfer through the cooling system. If leaks in refrigerant lines, damaged coils, or a defective expansion valve allow refrigerant to escape the system, it causes low refrigerant levels. The AC unit is unable to absorb and transfer enough heat. The system will run for hours on end as it attempts to bring the indoor temperature down to make up for this shortcoming.

Understanding the Issue: How to Diagnose Your AC Problems

Before talking about solutions when your air conditioner won’t turn off, it is essential to understand how an air conditioner works and how to diagnose issues correctly.

How Does an Air Conditioner Work?

Your AC pulls in warm air from your home through a fan. Inside the AC unit, a special liquid called refrigerant absorbs the heat from the warm air.

Then, the thermostat, like the AC’s brain, detects the room’s temperature. When it is too warm, it tells the AC to start the cooling process. The cooled air is then pushed back into your home, making you feel comfortable and refreshed.

This cycle continues until the thermostat senses that the room has reached the desired temperature, and it tells the AC to take a break.

The thermostat is your air conditioner’s best friend. It’s like the conductor of an orchestra, making sure everything plays in harmony. It checks the room temperature, detects when it is too warm, and sends the signal to the AC unit.

Once the desired temperature is reached, it acts as the cutoff signal. It can also control the fan, ensuring that the air circulates correctly.

Now that you understand the basis of how an air conditioner works, let’s talk about diagnosing problems. If you’ve found yourself wondering why your air conditioner won’t turn off in-house, then read on!

Diagnosing AC Problems

Do you know how to diagnose your HVAC system if your air conditioner won’t turn off? Here’s a simple process to follow.

  • Check the thermostat: Make sure the thermostat is set to the right temperature. Sometimes, it’s just a matter of adjusting the settings.
  • Airflow: Feel the air coming out of the vents. Is it weak or warm? Poor airflow can indicate clogged filters or duct issues.
  • Strange sounds: Listen for odd noises like squealing or grinding. Unusual sounds may indicate issues with the fan or compressor.
  • Leakage: Look for any signs of water or refrigerant leakage around the AC unit. Leaks need professional attention.

Seasonal Maintenance Checklist

As the cooling session begins and ends, follow this checklist:

Beginning of Cooling Season

  • Clean or replace the air filter.
  • Clear debris and vegetation around your outdoor unit.
  • Check all the vents are open and unobstructed.

End of Cooling Season

  • Inspect ductwork for any leaks or damage
  • Clean the evaporator and condenser coils to maintain efficiency
  • Verify that the thermostat is correctly set for the heating season.

Classic Heating & Air is a full-service, family-owned and operated heating and air conditioning contractor dedicated to serving all of your HVAC needs. We have plenty of service trucks constantly buzzing the metroplex so our technicians are never far away. That’s why we guarantee SERVICE WITHIN 2 HOURS OR IT’S FREE!

Our phones are answered 24 hours a day by Classic employees, so whether your situation is an emergency or a well-planned event we will be there when you need it most. We offer thousands of air conditioning and heating products, repairs, and services to ensure your home is a comfortable, healthy place.

At Classic Heating & Air, we guarantee to meet your comfort needs and exceed your service expectations. We take great pride in providing McKinney, Plano, and the entire Dallas metroplex with the best equipment, the best warranty, and the best customer service. Give us a call today at 214-310-COOL (2665) and let us show you The Classic Difference.