Dirty air filter: A dirty air filter can restrict airflow, which can make it harder for your AC unit to cool your home. If your air filter is dirty, it's recommended to replace it every 1-3 months. Low refrigerant: Refrigerant is a liquid that helps your AC unit transfer heat from inside your home to the outside.
Your AC might not cool properly due to thermostat issues, an undersized unit, or extremely high outdoor temps—so check those first. Keep an eye on airflow—replace clogged filters every 3 months, and make sure vents and ducts aren't blocked for efficient cooling.
Air conditioners make homes more comfortable on hot and humid days. So, it can be frustrating when the AC is not cooling below 75 degrees, even if it has been running for hours. Many factors can cause this issue, including clogged filters, refrigerant leaks and the wrong unit size.
One possible reason your AC is not reaching the set temperature is that the thermostat could be dirty. If dirt, dust, or other debris has accumulated within the thermostat box, it can cause the wires to heat up or other issues. Thermostats are cleaned during routine HVAC maintenance to help prevent this from happening.
Your AC unit isn't producing cool air as well as it used to because dirty coils may be hindering its ability to remove heat in your home's air. It could also not work properly due to a clogged filter and refrigerant running low, which are also the most common causes why you feel warmer these days.
Some of the most common thermostat issues include:
The thermostat is broken, not properly level, or dusty. The thermostat needs to be recalibrated. There is loose wiring causing a thermostat issue.
Check the thermostat settings.
Make sure the thermostat is set to the correct temperature and that it is set to "cool" mode. If the thermostat is set too high or is in "fan" mode, your AC won't cool your home effectively. Additionally, check the batteries in your thermostat to ensure they are not dead or low.
For many of us, 70 degrees is the ideal indoor temperature, but when it is close to 100 degrees outside, your AC unit will be working quite hard to meet these expectations. Consider setting your thermostat at 75 degrees to 80 degrees in your home if the outside temperature is approaching triple digits.
If it's 90 degrees outside, most people would set their AC to a perfectly comfortable temperature of 68-72°F.
If it doesn't go below 76 then your central air conditioning unit is probably undersized or the house is old and not insulated properly. Do you have old doors and windows that are letting hot air in? Close off the vents in the basement and make sure air isn't still flowing through them.
Well, certain problems can prevent an air conditioner from properly cooling down your home including: A dirty air filter. A blocked condenser. A refrigerant leak.
Since 72 degrees is generally agreed upon to be an ideal indoor temperature, most people would probably still feel comfortable setting their AC units slightly higher than this, perhaps at around 75.
How Often Do I Need to Change Out My Air Filter? Generally, most air filter manufacturers and HVAC companies recommend changing your air filter every 90 days, or 3 months. That can change based on where your home is located (ex. dusty, dry climates), if you have any pets, and the age of your system and equipment.
In the summer, experts say the thermostat for your air conditioner should be set to at least 78°F during the day when people are at home. That setting is designed to help people avoid high energy bills in the summer. The lower your thermostat setting, the higher your bill.
During heat waves, experts, including utility companies, recommend keeping your thermostat no more than 20 degrees cooler than the outdoor temperature. For instance, if it's 100 degrees outside, aim to set your thermostat to at least 80 degrees.
Cooling a house from 80 to 72 degrees is a common goal for many, especially during the peak of summer. On average, this process takes roughly two and a half to three and a half hours.
A common rule of thumb is that most models can function properly only above 68 degrees Fahrenheit. Any lower temperature will result in the system freezing up. In addition to a frosty refrigerant, the piping and coils could also become covered with ice.
To fix an AC not blowing cool air, ensure the thermostat is set to "cool" mode and the temperature is set lower than the current room temperature. Inspect the air filter as a dirty filter can restrict airflow. Ensure the condenser coils are clean and free of debris. Make sure vents are open and unobstructed.
The lowest outside temperature at which to run your AC is typically around 60-65 degrees Fahrenheit. At temperatures below this range, your air conditioner might not operate efficiently, causing increased energy consumption and potential strain on the system.
Start by making sure you have it set to your desired temperature and that it's switched to the “cool” setting. Next, double-check your vents to ensure they're open and free from obstructions. If that doesn't work, remove your A/C filter, and inspect it for any dust or discoloration.
A bad thermostat can be detected when your AC or furnace is not turning on, your HVAC systems are not turning off, the thermostat not responding, your HVAC system is short-cycling, the room temperature not matching the temperature displayed on the thermostat, and the programmed setting resetting themselves.
If the temperature is set to 74°F but the thermometer shows 78°F, you will have to recalibrate the thermostat to account for this 4-degree deviation. Even with older AC units or furnaces, you might have to recalibrate your thermostat from time to time.