What Is HVAC Short Cycling? | Causes & It’s Solutions

Air conditioners keep your home’s indoor environment up to par, whether it’s summer or winter. Yet, sometimes, they start getting off track. This means they turn off or pause it, and it’s working without reaching the temperature you set on the AC or furnace.

What Is HVAC Short Cycling?

In simple words, short cycling is a term in HVAC that refers to the air conditioner or furnace’s internal failure, which leads to shutting the whole system. This process repeats three cooling cycles each hour, during which the compressor runs for only 10 minutes. Once it passes, the system powers off to rest before starting again. Also, this short cycling occurs, and the compressor doesn’t run its entire course, so cool air does not circulate through your home.

7 Reasons for HVAC Short Cycling

Below are the 7 most common issues occur in the HVAC short cycling:

1. Thermostat Issues

First of all, a faulty thermostat is very challenging. These issues arise when a thermostat does not correctly read temperatures or is placed in parts of the home that receive direct sunshine or drafts. As a result, it assumes the wrong temperature and the system shuts down.

As someone who’s had to call in technicians to adjust or replace my thermostat, I can tell you that ensuring it is correctly calibrated and not affected by environmental factors like those corners where drafts are more prevalent can make a world of difference. I learned that having your thermostat near the kitchen or under direct sunlight is a poor idea.

Why?

Because the heat from cooking can trick your thermostat into activating the AC when the house is perfectly cool, you should upgrade to a digital thermostat or even a better Wi-Fi-compatible model to resolve these issues.

2. Addressing Low Refrigerant/Refrigerant Leak

How will your car respond when it’s running out of fuel?

You know better!

The same goes for the AC. Low-level refrigerant leaks pose a risk to the compressor. In heat pump systems, you have to maintain refrigerant circulation. The closed loop is crucial because any leak allows air to escape and pressure to drop.

Thus, the chemical reaction relies on highly pressurizing the fluid; without it, your AC unit might short-cycle.

3. Leaking Air Ducts

In my experience, one often overlooked culprit behind short cycling in AC systems is leaked air ducts. Many homes have ductwork made with an internal metal coil that acts as a frame, and air-tight insulated plastic wrap surrounds most common setups in attic interior walls.

Since these are constantly subjected to extreme temperatures, over time, the outer wrap can break down and form cracks through which the direct air from outside enters the system. This regulation forces the AC to work harder to achieve the desired temperature.

4. Dirty Air Filters

Likewise, air filters are another common reason for HVAC issues. As someone who prides themselves on keeping a well-maintained home, I’ve learned not to underestimate the importance of checking the HVAC system’s air filter.

Over time, filters can get clogged with dirt, dust, skin flakes, cooking smoke, and pet odors—all sorts of horrible stuff you don’t want circulating in your air. That’s why Ventiluxes technicians recommend changing the HVAC system filter at least after 3 – 6 months.

Note: If you have smokers in the house or do a lot of cooking, you might need to change it more frequently.

5. Electrical Issues

Sometimes, the issue isn’t the components but the improper installation. Due to high wear and tear, some components become faulty. They may even lose or have improper connections. As a result, the system triggers to shut off too soon. In this case, if the thermostat is not set to the correct mode, it can inadvertently become a leading cause of short cycling. We’ve had some clients who simply forgot to switch their thermostat settings, leading to unexpected system behaviors.

6. Frozen Evaporator Coils

Just like you can’t cook frozen meat immediately, frozen evaporator coils cannot operate the HVAC. This typically happens due to poor maintenance. The common reason is dust on both the evaporator coil and the air filters. This creates a thick layer of dust that makes it difficult for the coil to absorb heat from the air.

As the unit tries to cool your home, this insulating layer can lead to condensation on the coils, which then freezes. This impairs the system’s ability to cool and causes a short cycle.

7. Wrong Size HVAC

Another significant factor is whether the unit is too small or too large can have a substantial impact. A small unit will continuously cycle to maintain the indoor air temperature. It’ll struggle to keep up and shut down prematurely.

Conversely, a bulky AC will cool and heat your home too fast. As a result, it will turn off before reaching the ideal temperature threshold.

7 Tips for Fixing Your System’s Short Cycling

When the HVAC system begins short cycling, it’s vital to address these minor issues quickly to prevent further damage.

Here are some practical steps to troubleshoot and resolve common causes of short cycling.

The Bottom Line

We hope you understand when your HVAC is causing short cycling and will fix it as asap. Or you can schedule regular maintenance checks from Ventiluxes. So, all parts of the HVAC system are in good working condition.