AC Stops Working When It’s Hot Outside

Here is a list of possible reasons air conditioner stops working when it is hot outside, in order of most common to least common:

1. Clogged Filters:
   • If your system’s air filters are clogged with dirt, dust, or other debris, the airflow to the evaporator coils can be restricted. This could lead to reduced cooling and cause the system to shut down to prevent further damage.
2. Dirty Condenser Coils:
   • The AC unit’s condenser coils, which are located in the outdoor unit, are responsible for releasing heat from the refrigerant. If these coils are dirty or covered in debris, they can’t dissipate heat effectively, causing the system to struggle and potentially shut down.
3. Refrigerant Problems: 
   • Low refrigerant levels or refrigerant leaks will significantly impact the cooling capacity of your air conditioner. In hot weather, the system might struggle to cool the air properly and shut down as a protective measure.
4. Electrical Issues:
   • Heat can contribute to electrical problems in the AC system. Wires, connections, capacitors, motors, or other electrical components can expand due to heat and/or cause short circuits or other electrical failures.
5. Overload:
   • When the outside temperature rises, more people use their air conditioners, which can put a strain on the electrical grid. If the power supply becomes overloaded, it could lead to power outages or voltage fluctuations that affect your air conditioner’s operation.
6. System Age and Wear:
   • Older air conditioners may not be as efficient at cooling, especially during extremely hot weather. Wear and tear over time weakens the system and can lead to problems that cause the system to shut down.
7. Compressor Issues:
   • The compressor, located in the outdoor unit, is a critical part of your air conditioning system that circulates the refrigerant and helps cool the air. High temperatures outside can make the compressor overheat and get damaged, which would shut down the entire system.
8. Maintenance and Servicing:
   • It goes without saying, but regular maintenance is so important to keep your air conditioner in good working condition. If your system hasn’t been properly maintained, it’s more likely to have problems, especially when it’s working harder in hot weather.

If your air conditioner acts up or completely stops working during hot weather, turn it off and let it cool down for a while. Check the air filters, make sure there are no obvious issues with the outdoor unit, and make sure that the thermostat is working correctly. If you can’t identify or fix the problem yourself, then contact a professional HVAC technician for diagnosis and repair.

Prepare Your AC System for Hot Weather

You should prepare your air conditioning system before hot weather or summer to be sure it operates efficiently and effectively. Here are some steps you can take in advance:

1. Schedule Preventive Maintenance:
   • Have a professional HVAC technician to perform a complete inspection and perform maintenance on your air conditioning system. They can clean components, check for any issues, and make sure the system is performing as expected.
2. Clean or Replace Air Filters:
   • Dirty or clogged air filters restrict airflow and reduce your system’s ability to cool properly. Clean or replace your air filters regularly, usually every 1-3 months.
3. Clear Surrounding Area:
   • Make sure there is no debris, leaves, or other obstructions around the outdoor unit. Keep a clear space of at least 2 feet around the outdoor unit to allow for airflow.
4. Check Thermostat:
   • Make sure your thermostat is working correctly. If you don’t already have one, consider getting a programmable thermostat that adjusts the temperature based on your schedule, which helps save energy when you’re not at home. Ideally, get one that connects to your wi-fi network with an app that allows you check and control your AC system when your away from home.
5. Inspect and Clean Condenser Coils:
   • The condenser coils in the outdoor unit get dirty over time, reducing their ability to release heat. Gently clean them using a soft brush or hose. Turn the unit off before cleaning the coils.
6. Test the System:
   • Before hot weather kicks in, turn on your air conditioning system to make sure it’s cooling properly. If you discover a problem, you can address it before the heat becomes unbearable.
7. Check Refrigerant Levels:
   • Low refrigerant levels can indicate a leak in your system. If your system is not cooling as well as before, contact an HVAC technician to check the charge and recharge the refrigerant if needed.
8. Inspect Ductwork:
   • If you have a central air conditioning system, check the ductwork for leaks, cracks, or damage. Sealing and insulating your ducts can help improve efficiency and prevent excessive debris from accumulating in the ductwork.
9. Consider Upgrades:
   • If your air conditioning system is older (10+ years), you should consider upgrading to a more energy-efficient model. Newer units are designed to use less energy and provide better cooling.
10. Use Ceiling Fans:
    • Ceiling fans help distribute cool air more evenly throughout your living spaces. You can set your thermostat a few degrees higher without sacrificing comfort.

• :Close Curtains and Blinds
  • During the hottest parts of the day, close your curtains and blinds to block out direct sunlight and reduce the heat entering your home. This will reduce the strain on your AC system.

12. Practice Energy Efficiency:
    • To reduce the strain on your air conditioning system and save energy, avoid using heat-producing appliances (like ovens) during the hottest hours of the day.