How to Fix a Short Cycling AC: Tips You Should Follow

How to Fix a Short Cycling AC: Tips You Should Follow

An air conditioner (AC) is a lifesaver during scorching summers, but what happens when it doesn’t function properly? Short cycling is a common AC issue that disrupts your cool comfort and can even damage your unit.

This comprehensive guide explores everything you need to know about ac short cycling, from understanding the problem to troubleshooting and fixing it.

What is a Short Cycling AC unit?

An AC unit short cycling goes through a cooling cycle where it turns on, removes heat from your home, and then shuts off once the desired temperature is reached. Short cycling disrupts this natural process. Meanwhile, AC compressor short cycling results in:

  • Increased Energy Bills: The frequent on-and-off cycles make the AC work harder, leading to higher energy consumption.

6 Common Causes of Short Cycle Ac

Several factors can cause your AC to short cycle. Here are some of the most common causes of short cycling:

Dirty Air Filter:

The AC shuts off to prevent freezing, but the restricted airflow prevents proper cooling, leading to short cycling.

Low Refrigerant Charge:

Refrigerant is the lifeblood of your AC system. Low refrigerant levels reduce the system’s ability to absorb heat, causing the compressor to shut off prematurely.

Frozen Evaporator Coil:

If the refrigerant level is low, it can become excessively cold and freeze. This triggers a short cycle a safety shut-off, leading to short cycling.

Incorrect Thermostat Setting:

A faulty thermostat or an incorrect setting can trick the AC into thinking the desired temperature has been reached, causing it to shut off prematurely.

Oversized AC Unit:

It shuts off before properly dehumidifying the air, leading the thermostat to call for cooling again shortly after, resulting in short cycling.

Blocked Outdoor Unit:

Debris like leaves, twigs, or overgrown plants around the outdoor unit can restrict airflow, causing the unit to overheat and shut off prematurely.

Troubleshooting Short Cycling AC: Before You Call a technician

Nighttime temperature fluctuations can also contribute, and similar issues can cause car AC compressors to short cycle.

  • Check the Air Filter: Most filters need replacement every 1-3 months during peak cooling season.
  • Inspect the Thermostat: Ensure the thermostat is set to “cool” and the desired temperature is accurate.
  • Clear Obstructions: Remove any leaves, or twigs blocking the airflow around the outdoor unit that cause ac is short cycle.

When to Call an AC Technician

If the above troubleshooting steps don’t solve the issue of how to fix short cycling AC, it’s time to call a qualified HVAC technician.

  • Refrigerant Recharge: If the refrigerant level is low, a technician can safely add the required amount to restore proper cooling and prevent short cycling.
  • Evaporator Coil Cleaning: In case of a frozen coil, the technician will thaw it out and identify the underlying cause of freezing (dirty filter, low refrigerant) to prevent future occurrences.
  • System Inspection and Repair: The technician can inspect the entire AC system for any other underlying issues that might be causing the short cycling.

Short Cycling AC in Portable Units

Portable AC short cycling is susceptible as well. The most common causes for portable ACs include:

Full Drain Tank:

Portable ACs collect condensate during operation. A full drain tank can shut off. Empty the drain tank regularly to prevent short cycling.

Improper Vent Hose Installation:

The vent hose expels hot air from the portable unit. If the hose is kinked, blocked, or too long, it can restrict airflow and cause short cycling. Ensure the hose is properly positioned and not exceeding the recommended length.

Undersized Unit for the Space:

Similar to a large central AC unit, a portable AC unit that’s too small for the room will struggle to maintain the desired temperature, leading to short cycling. Consider the size of the room when choosing a portable AC unit.


The car AC compressor is short-cycling, causing it to turn on and off frequently. There are several reasons why your car AC compressor is short cycling. So, if your car AC is short-cycling, it leads to inefficient cooling and potential system issues. By following these tips on car AC short cycling, you can troubleshoot and potentially fix a short cycling AC unit.