Q&A: “Why is my AC running constantly but the house is still 78 degrees?”

When July heat settles in, your air conditioner may feel like it is working nonstop just to keep up. But if your AC is running constantly and your home is still stuck at 78 degrees, something is likely preventing your system from cooling properly. For homeowners relying on air conditioning in Lake in the Hills, this issue often points to airflow problems, frozen coils, low refrigerant, or a system that needs professional service.

At 24-Hour Home Comfort Services, we know how frustrating it is when your AC runs all day, but your home still feels warm. Below, we answer common questions and explain what you can check before calling our team.

Why Is My AC Running but Not Cooling Enough?

Your AC should remove heat and humidity from your home, then cycle off once the thermostat setting is reached. When it runs continuously without lowering the temperature, the system may be struggling to absorb or release heat.

Common causes include a dirty air filter, blocked vents, a frozen evaporator coil, low refrigerant, dirty outdoor condenser coils, or an aging system that can no longer handle peak summer demand. In July, frozen coil and refrigerant issues become especially common because your AC is under heavy strain.

Could a Frozen Coil Be the Problem?

Yes. A frozen evaporator coil can stop your AC from cooling even while the system keeps running. This often happens when there is not enough warm air moving across the coil. The coil gets too cold, moisture freezes on it, and eventually airflow is restricted even more.

Signs of a frozen coil may include weak airflow, warm air from the vents, ice on refrigerant lines, water around the indoor unit, or a system that seems to run endlessly. If you suspect ice, turn the cooling off and set the fan to “on” to help thaw the coil. Do not chip away at the ice. Once thawed, call us so we can find out why it froze in the first place.

What About Low Refrigerant?

Low refrigerant can also cause your AC to run constantly without reaching the thermostat setting. Refrigerant is what allows your system to absorb heat from inside your home and move it outdoors. If the refrigerant level is low, your AC may lose cooling capacity, and the coil may freeze.

Refrigerant does not get “used up” like fuel. If levels are low, there is usually a leak that needs to be located and repaired. Simply adding refrigerant without addressing the leak is not a long-term solution.

What Can I Check Before Calling?

Start with the basics. Replace a dirty air filter, make sure supply and return vents are open, clear grass and debris around the outdoor unit, and confirm your thermostat is set correctly. If airflow is weak, the outdoor unit is not running properly, or the system still cannot cool below 78 degrees, it is time for professional troubleshooting.

When Should I Schedule AC Service?

If your AC has been running for hours with little temperature change, do not ignore it. Constant operation can increase energy bills, strain components, and turn a small repair into a major breakdown. Our technicians can inspect airflow, refrigerant levels, coils, electrical components, and overall system performance to restore reliable comfort.

You can always count on 24-Hour Home Comfort Services, your heating and cooling specialists.