Tips for Fixing a Constantly Running AC Unit

On an average summer day in Southern California, you should be able to expect your air conditioner to keep you cool and comfortable while running in 15 minute cycles. But if your system is running in cycles of 30 minutes, or even an hour, then there is a good chance that there is something wrong.

When your air conditioning unit is the proper size and regularly maintained, it can help to keep you comfortable during the hot, summer days without running constantly all day long. Not only will over-running create cooling issues in your home, it is also going to increase your electricity costs, while putting undue stress on your unit.

An efficient, well-functioning AC unit will run frequently during the summer months. But you can tell it is over-running when you notice:

  • The unit runs for longer periods of time without changing the temperature in the home
  • There’s uneven cooling in the home
  • Unexpected increases in electric costs

Each of these are symptoms that your unit is not running properly. Some of the specific reasons this may be happening are found here.


What Causes AC Units to Run Constantly?

There are five categories of problems that can cause your home’s central AC to run constantly. They include:

  • AC Unit Is Improperly Sized

When a new air conditioner is installed in your home, your contractor will fit the unit to ensure that is not too large and not too small for the size of your home. If the air conditioner that you have is too small, it will run all the time because it lacks sufficient power to meet your home’s cooling demands. If the unit is too large, then it can result in inefficiency, uneven cooling and increasing electrical costs.

  • Is the Unit Too Small? A unit that’s too small must work harder and longer to cool the home. This increases the wear and tear on the unit, which will shorten the unit’s life. Additionally, this can cause costs to rise, due to the added runtime necessary to cool the home.
  • Is the Unit Too Large? An AC unit that is too large will run for shorter periods of time but not long enough to remove moisture from the air. As a result, the home will have damp, clammy air. Additionally, because it runs for shorter periods, it turns off and on more, causing wear and tear issues to occur more quickly.


Signs this is the problem:

  • You just got a new air conditioner
  • Air from vents is cool and the airflow is normal, but your home does not reach the thermostat temperature on hot days.
  • Frozen evaporator coil (refrigerant tubes in the inside unit)


  • AC Unit Is Too Old

As air conditioners get older, they begin to lose their ability to properly cool your home. Various system components can begin to become inefficient, and your air conditioner will have to run much more often than it used to in order to keep your home cool. A new air conditioner will not only have shorter cooling cycles, but will also consume much less energy. Replacing your home’s AC unit with an energy-efficient model will reduce runtime and can help to keep your home more evenly cooled.

On average, an AC unit lifespan stands at 10 to 15 years, but if you have an HVAC system, it could last as long as 20 years. Of course, your old AC system has to be well maintained to last that long functioning efficiently.


Signs this is the problem:

  • You have to call for repairs frequently
  • The AC does not cool the house evenly
  • Your house feels humid
  • The unit emits odors
  • Your energy bills are rising
  • Your unit require R-22 refrigerant
  • Your home


  • Your AC Requires Maintenance

Irregular maintenance is one of the most common causes of AC inefficiency. It is recommended that you have your unit serviced at least two times a year – once in the winter and once again in the spring. Regular maintenance ensures the coils, ducts, and air filters are clean, which maximizes airflow and cooling power.

A few common maintenance issues include:

  • Dirty condenser
  • Clogged or restricted air filters
  • Low refrigerant charge
  • Dirty evaporator coils


Signs this is the problem:

  • Air from vents is cool but the airflow is weak
  • Dirty air filter
  • Closed and or blocked vents
  • Improperly sized or damaged ductwork
  • Frozen evaporator coil
  • Bad blower motor


  • Thermostat Problems

Your home’s thermostat is what tells your AC unit what the current temperature in your home is. If the thermostat is faulty and it does not register the current temperature properly, the unit will run longer and stop running too soon. The result is usually going to be a home that is not cooled evenly.

Test your thermostat by putting a thermometer close to it. Make sure the read outs are very close and if they aren’t you may need to have your thermostat replaced.


Signs this is the problem:

  • Thermostat has no power
  • Inconsistent temperatures from room to room
  • Changing the batteries did not help
  • The air conditioner or furnace runs constantly and will not turn off
  • The air conditioner or furnace will not start


  • Your Home Has Air Leaks

Air leaks can develop around your windows and doors, as well as in your ductwork. These leaks allow conditioned air to escape your home, which means your air conditioner has to keep producing more cool air and runs more often than it should. Insulation and well-sealed ductwork contribute to the efficiency of your AC unit. A home that is drafty, or that has old, improperly sealed ductwork will “leak” cool air out. Properly insulated windows, ductwork, and attic spaces can all improve the efficiency of your HVAC unit.


Signs this is the problem:

  • Higher energy bills
  • Cold spots along the walls
  • You can see daylight around a door or window frame


Final Thoughts

There are two main issues with your air conditioner running more often than it should. The first problem is that it’s a big waste of energy. The more often your air conditioner runs, the more energy it will consume and the higher your utility bills will be. The second problem is that it will put a lot of stress on your system and its components, which can lead to breakdowns and the need for repairs.

If your system needs repair or inspection before winter, call us at 951-926-1002. You can also visit our Contact page and complete the contact form.