opening the lid of the mini split HVAC unit

When an HVAC turns on and off in rather quick successions, without running for longer periods, this is called short cycling. It’s fairly common, but when this happens it means there’s something wrong with your HVAC. So what should you do?

Don’t leave these occurrences alone. Short cycling takes a toll on the compressor motor, fan motor, controls, or other components, often leading to costly repairs or full system failure. Over time, continued short cycling, if not properly addressed, can acutely shorten the life span or your unit.

It can also increase your energy costs. Short cycling causes the unit to turn off and back on at intervals of less than five to ten minutes. This means your unit is running much more than it should and this will lead to costly increases in your energy bills!

Short cycling usually indicates a larger problem that could lead to permanent damage of your unit, thus requiring a costly replacement.

What should I do if my HVAC is short cycling?

Whenever your unit is doing things that are out of the norm, such as short cycling, it’s best to give us a call. We can have one of our a highly-skilled and knowledgeable Certified Comfort Specialists come and inspect your unit as soon as possible.

Don’t delay, call us today so we can get your system back to its most efficient state while avoiding costly repairs or even a replacement down the road!

While there are many possible reasons for short cycling, here are several of the most common ones and what can be done to fix them.

Cause 1: Low Refrigerant

The coolant that flows through your system, helping to absorb heat and cool the air inside your home, is called refrigerant. You may know it by one of its brand names—Freon®. When your refrigerant is low, the needed compressor-pressure levels are affected. This triggers your compressor’s low-pressure control, shutting off your compressor. 

When the pressure rises and triggers your unit to restart, this causes the short cycling. If your refrigerant level is low, this indicates your unit has a leak, as refrigerant is cycled throughout the compressor, not burned off.

Low refrigerant can also cause frozen coils. One of our professionals can find your leak and prevent any further issues or damage.

While our professional is looking at your refrigerant, be sure to have a conversation about the type of refrigerant used in your unit. To be consistent with the 1987 Montreal Protocol, the US Environmental Protection Agency (EPA) has mandated regulated changes to all HVAC refrigerant here in Florida and across the United States. Your system may be affected.

Cause 2: Thermostat Location

Your thermostat acts as the sensor for your heating and cooling system, telling it when to cool your home. If its location is not optimal, such as near a window or too close to a vent, your thermostat will be sending misleading information to your system. 

Suppose your thermostat is in the direct line of a vent’s airflow. This will cause the thermostat to think it’s cooler in your home than it really is, and your unit will shut off thinking it’s reached its desired temperature. Since the cool air is no longer flowing through the vent, the thermostat realizes your home is actually still too warm and triggers your unit to start up again. This is short cycling. Be sure your thermostat is located in a central location away from direct sunlight and vents.

Cause 3: Dirty Air Filter & Regular Maintenance

Regular maintenance of your HVAC unit is essential to its efficient operation. When you skip your maintenance, issues such as dirty air filters, condensate switch issues, objects stuck in your vents or a corroded flame sensor are some of the most common issues that can cause short cycling. One of the most easily remedied problems we see here in Southwest Florida is dirty air filters. The dirty filters restrict airflow, which in turn causes so many problems, one of them being a frozen coil. This can cause your air conditioner to malfunction and short cycle. Be sure to maintain your unit and change your filters regularly to avoid these type of costly issues.

Cause 4: Oversized Air Conditioner

An HVAC unit that’s too large for your home short cycles because it cools your home too rapidly. But because it cools so quickly, it doesn’t dehumidify properly, causing your unit to shut down and start up frequently. 

You will more than likely also find your home has hot and cold spots, and you will experience higher energy bills. If your unit is newly installed, talk to the technicians who installed it to see what they can do to help you. 

You want to be sure a Manual J heat load calculation (an Air Conditioner Contractors of America [ACCA] approved method of calculating house cooling loads) is always performed when determining the proper size heating and cooling system for your Fort MyersEstero and Naples, FL, home. Call our qualified professionals to do a Manual J at your home to determine if your current unit is appropriately sized.

Contact Certified Heating and Cooling Today

Short cycling causes a whole host of problems with your air conditioner. If you notice your air conditioner behaving like this, call one of our Certified Heating and Cooling professionals at 239-205-8342 or request service online to assess the situation. You want your air conditioner to cool efficiently and to last for years to come. Short cycling will short change you.

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