You program the thermostat to a comfortable setting and then expect that your AC should cool down in a reasonable amount of time. It is already a couple of hours later, and the AC is still running, but the house is still hotter than it should be. The system never seems to catch up.

If the above sounds familiar, you are not the only one! It is a frustrating issue many homeowners have during the summer months. Some causes can be easily sorted out, but other causes may require professional assistance.

So, let us now discuss some of the common reasons for why your AC is constantly working without reaching the required temperature level.

1. Dirty Filters Impede Airflow

The most common and often forgotten is a clogged-up air filter.

Your air filter prevents dust, pollen, pet hair, and other airborne particles from entering your HVAC system. These contaminants accumulate over time and limit airflow. The less air that flows through the house, the harder your air conditioning unit will have to work to push cool air throughout the home.

Common signs include:

• Poor airflow from vents
• Rooms cooling unevenly
• Higher utility bills
• Longer cooling cycles

Luckily, this can easily be fixed most of the time. Inspect and replace your air filter at least once every 3 months. Dirty filters are a major reason for systems that do not achieve the desired temperature.

2. Thermostat Problems

The thermostat can give false readings if it is not calibrated correctly, if it is placed in direct sunlight, near heat-producing appliances, or if it just does not work. This can lead to a constant running of the AC.

Also, homeowners sometimes find that the setting for the thermostat fan is set to “On” rather than “Auto.” This setting is ongoing, with the fan operating at all times, giving the impression that the system is on 24 hours a day.

Some simple things to do to check the thermostat are:

• Check that the thermostat is in the “Cool” setting
• Make sure that the fan is turned to “Auto.”
• Inspect the battery for dead batteries.

Readings may be inaccurate if this is the case; repair or calibration by a professional may be required.

3. Low Refrigerant Levels

Refrigerant is the compound responsible for extracting heat from the inside of your system and moving it outside. Refrigerants in the unit need to be present to ensure effective cooling.

Unlike fuel, the refrigerant is not used up in the course of its operations. Inadequate amounts often point to a leakage elsewhere in the system.

Common signs and symptoms are:

• AC runs constantly
• Hot or warm air from vents
• Accumulation of ice on refrigerant lines.
• Hissing sounds
• Rising energy bills

Low refrigerant levels will help the unit run under high pressure, although not with much cooling power. As such, there may be instances where the AC does not get down to the set temperature levels. It is recommended that you have an HVAC expert handle this problem.

4. Dirty Evaporator and Condenser Coils

There are two important sets of coils that your air conditioner needs.

The condenser coil on the outside will give off heat, and the evaporator coil within will absorb heat. If either coil develops a dust, dirt, or debris layer, the heat transfer will be reduced.

The result? Your AC will work for longer durations, but at a reduced cooling capacity.

The outside condensing units are highly vulnerable to:

• Clipped grass
• Leaf coverage
• Soil buildup

If coils are cleaned regularly, then they will work perfectly well and will not work too hard. Over time, soil is one of the major causes of cooling efficiency reduction.

5. Damaged Air Conditioner Parts or Components

Even when your air conditioner system is operating well, you may not be receiving enough cool air because of problems within the ducting system. The ducts are found within attics, crawl spaces, or even the walls within a house. Problems that include cracks, holes, or detached spots result in the leaking of air and the inability to reach the destination.

This means:

• The AC operates for a longer period of time
• Certain rooms stay warm
• Energy bills increase
• Indoor comfort suffers

Sometimes, homeowners end up losing a considerable amount of cool air due to duct leaks and just do not even realize it. A duct investigation by a professional will locate places where air is lost and re-establish the system's effectiveness.

6. A Condenser That Is Too Small

The issue may not be due to a fault, but simply because the equipment is too large.

Each home needs a cooling system that is the correct size for the house, considering these:

• Square footage
• Insulation levels
• Window placement
• Ceiling height
• Local climate

AC units that are undersized for a home's cooling requirements can run for nearly all of the day on hot days and may not even be able to achieve the set temperature.

Many homeowners think that the larger the better, but it is important to size it right. A load calculation is a process undertaken by an HVAC contractor to see if your HVAC system is properly sized for your home.

7. Poor Insulation and Air Leaks

The AC does not work in isolation. The condition of your house truly impacts how comfortable your living environment is. If cool air escapes through the windows, doors, attic, and even cracks in the walls due to improper sealing, then the AC will fail at cooling.

Common contributors include:

• Inadequate attic insulation
• Drafty windows
• Poor weather stripping
• Air leaks around doors
• Unsealed attic access points

When the warmth sneaks in faster than the AC can kick it out, the system might run constantly without ever hitting that set temperature. Sealing those leaks and boosting insulation usually makes a big difference in both comfort and efficiency.

Conclusion

An air conditioning system running non-stop without hitting the set temperature is just annoying; it is a warning. Problems like restricted airflow, low refrigerant, filthy parts, duct leaks, or a wrongly sized setup could be the culprits. Getting these diagnosed early can boost comfort and lower those energy bills.

Riley Heat & Air helps homeowners spot the real issues behind cooling troubles.