How to make sure your air conditioner is working properly?

Author: Alena Feil  |  Last update: Tuesday, December 30, 2025

7 Simple Checks to Ensure You AC System is Working Properly
  1. Check the Air Vents. ...
  2. Test the Temperature From Supply and Return Registers. ...
  3. See What Happens When You Adjust the Thermostat. ...
  4. Look at the Outdoor Unit. ...
  5. Examine Your Evaporator Coils. ...
  6. Consider Any Strange Sounds or Smells. ...
  7. Look for Water From the Drain Pipe.

How do I tell if my air conditioner is working properly?

A good indicator that your AC works efficiently is if the ambient temperature drops at least one degree every 20 minutes. As an additional note in keeping your AC strong and healthy, refrain from overheating the home. This is not in regards to using the furnace but letting ambient temperature rise too high.

Why is my AC running but not cooling well?

There are a number of reasons why your air conditioner might be running but not cooling. It could be an issue with the thermostat, the compressor, or the evaporator coils. Or, it could simply be clogged with dust and debris, which is preventing it from working properly.

How cool should my house be if it's 100 outside?

When temperatures exceed 100 degrees Fahrenheit outside, setting your air conditioning (AC) to around 75-78 degrees Fahrenheit is generally considered efficient. Here are some reasons for this recommendation:

Is 72 a good temperature for air conditioning?

Setting your air conditioning to 72°F is generally considered a comfortable indoor temperature for many people. It strikes a good balance between comfort and energy efficiency, making it a popular choice for residential settings.

AC Not Working Right? How to Check if Your Air Conditioner is Working Properly

What should AC be set at in summer?

The recommended rule of thumb for summertime is to set the temperature to 78 degrees Fahrenheit when you're home and higher when you're away. In general, set it to 82 degrees Fahrenheit when you're asleep and 85 degrees Fahrenheit when you're away.

Why is my AC set to 74 but reads 78?

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.

How cool should my house be if it's 110 outside in summer?

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.

How long should it take to cool a house from 90 to 72?

Cooling a house from 90 degrees to 72 degrees typically takes about 2 to 4 hours, depending on various factors.

Is 75 too hot for AC?

If this is the case, it may be necessary to keep your thermostat set at 72-74 degrees until everyone goes to bed. This can also depend on the number of people living in the house, or even whether you're preparing a home-cooked meal. If it's just you and your spouse, you may be fine with the temperature set at 75-77.

Should I turn off AC if it's not cooling?

Yes, you should turn off your AC if it's not cooling.

What is the first thing to check when the AC stops working?

Check these issues when the unit won't kick on: Check the thermostat and adjust the settings if it isn't set to Cool and an appropriate temperature setting to call for cooling. Examine the house circuit breakers for the AC unit and reset any tripped breakers. Check the air filter and replace the filter if it's dirty.

Can I clean my air conditioner myself?

To clean the coils, spray the fins on the inside of the unit with an A/C coil cleaner, following the manufacturer's instructions. To remove the cleaning detergent, spray with a hose to push the cleaner through the fins to the outside of the unit. Don't use a pressure washer — the force of the water can damage the fins.

Why is my AC running but not cooling?

This can occur when there are blockages or restrictions in the air ducts, preventing the cool air from reaching your home. Common causes of airflow problems include dirty air filters, blocked vents, and debris in the air ducts.

How to check if AC is cooling or not?

How Can I Tell If My A/C is Working Properly?
  1. Air Filter Inspection. Checking your air conditioning unit's air filter is one place to start to make sure it is working properly. ...
  2. Circuit Breaker Check. ...
  3. Check Batteries on Thermostat. ...
  4. Consider the Weather. ...
  5. Thermometer Test.

How cool should my house be if it's 90 outside?

Some of the basics include: turn your thermostat up a couple degrees and deal with 76 to 78 degree temperatures indoors for a few days. close off unused rooms. close doors and vents.

Why is AC not blowing cold air?

First, check your filters and coils for dirt and debris that may be impeding airflow. Once you've cleaned the filters and coils, run the air conditioner with just the fan so that the ice accumulation can melt off. If the AC still doesn't blow cold air, it could be that refrigerant levels are too low.

How long should AC run to cool 1 degree?

Air conditioners don't defy time; they follow a cycle that's affected by more than just a glance at the thermostat. Typically, it takes about an hour for an average-sized air conditioning unit in typical conditions to lower room temperature by one degree Fahrenheit.

Does keeping the AC at 72 save money?

Best AC Temperature Settings While You Are Home

As you consider the most comfortable room temperature for your lifestyle and family, keep in mind that for each degree that you set your thermostat above 72 degrees, you can save up to 3% on your energy bill.

Should AC be on auto or on?

There are benefits to having your air conditioner set to “auto” and “on.” The benefits of the “auto” setting include higher efficiency, lower energy bills, better humidity control, less wear and tear on some components, and quieter running.

Is 68 too low for AC?

During a heatwave, we recommend that you don't lower the AC's setting below 68°F. This is already quite chilly for most people, and many would consider it too cold. An air conditioner set this low risk of its coil freezing—and that's bad news because it indicates that the air conditioner is overworked.

Why is my AC struggling to cool my house?

Proper airflow is crucial for an AC system to cool your home efficiently. Several factors can compromise airflow, including blocked or obstructed vents, closed or incorrectly adjusted dampers, and dirty or obstructed evaporator coils. These issues restrict the air's flow, reducing the system's cooling capacity.

Is 82 too high for AC?

While ENERGY STAR suggests 82 degrees, that may be too uncomfortable for most families. Most people sleep better when their sleeping area is chilly, so that's why the National Sleep Foundation advises 60–67 degrees.

How to tell if a house thermostat is faulty?

7 Ways to Tell Your Thermostat Is Broken
  1. The Thermostat Has No Power. ...
  2. The AC or Furnace Won't Turn On. ...
  3. The Heater or AC Won't Turn Off. ...
  4. The Thermostat Reading Doesn't Match the Room Temperature. ...
  5. The Thermostat Doesn't Respond. ...
  6. The HVAC System Is Short Cycling. ...
  7. The Thermostat Forgets Programmed Settings.

Previous article
When to use oil-based primer?
Next article
Does putting ice in front of a fan make the air cooler?