One of the more common air conditioning system malfunctions property owners in the Mount Prospect area encounter is short cycling. This problem affects cooling efficiency, can cause long-term system damage, and leads to unnecessarily increased utility bills.
Leith Heating & Cooling, the leading AC repair specialist in Mount Prospect, IL, delivers this post to provide information about AC short cycling, its causes, and how HVAC professionals fix the problem.
What Is AC Short Cycling?
AC short cycling describes the situation where your cooling system turns on and off frequently without actually completing a full cooling cycle.
For most houses, a typical air conditioner’s normal cycle should take 15 to 20 minutes to complete. It usually takes that long to properly remove inside heat and dehumidify air effectively.
Short cycling interrupts the cooling and dehumidifying process. It causes the system to turn back on quickly, only to shut down again before completing a proper cycle. The premature shutoff usually occurs before indoor temperatures have reached the temperature set on the thermostat.
Signs Your AC Is Short Cycling
The common symptoms of a short cycling malfunction include:
- Frequent on/off cycles. Air conditioners that often run less than 10 minutes before shutting off are almost certainly not completing a normal full cooling cycle.
- Inconsistent indoor temperatures. Modern HVAC systems should provide consistent cooling throughout a house. If some rooms in your home are cooler or hotter than others, or if you notice rapid temperature swings, the system could be short cycling.
- High energy bills. Short cycling leads to wasted electricity, which usually translates to spikes in utility bills.
- Excessive humidity. Air conditioners remove excess moisture as well as heat. If your cooling system is short cycling, you may notice unusually high relative humidity levels indoors.
Common Causes of AC Short Cycling
These are some of the most common problems that lead to short cycling trouble.
Dirty or Clogged Filters
Clogged filters restrict airflow, causing system overheating. Most cooling systems respond to overheating by shutting down to protect the unit from permanent damage. Of course, this means the system turns itself off before completing a full cooling cycle.
Thermostat Issues
The thermostat operates as the brain of your cooling system. It provides signals to the system when it should cycle on or off. If it malfunctions, the system becomes prone to short and irregular cycling.
Improperly placed thermostats also cause cycling problems. Proximity to windows, doors, or appliances that produce heat often causes false temperature readings.
Frozen Evaporator Coils
Frozen evaporator coils typically occur because of restricted airflow or low refrigerant levels. When coils freeze up, the system can short cycle without providing adequate indoor cooling. If you see ice or frost buildup on outdoor evaporator coils, shut the system off completely and call an HVAC professional.
Leaking Refrigerant
Low refrigerant levels caused by leaks cause short cycling as the cooling system struggles to remove heat and moisture from indoor air effectively.
Electrical Issues
Faulty wiring, loose connections, or malfunctioning control boards can cause erratic cooling system function, including short cycling. Most systems automatically shut down when voltage irregularities trigger internal breakers to protect against damage or fire hazards.
Incorrectly Sized Unit
An oversized unit cools the home too quickly — causing the AC to shut off before completing a full cycle.
An undersized unit struggles to maintain the temperature set at the thermostat, leading directly to overheating and system shutdowns.
How HVAC Professionals Fix AC Short Cycling
Expert cooling system technicians perform various services to address short cycling issues.
Replace or Clean Filters
Many times, the easiest and most apparent fix is the most effective. Replacing or cleaning clogged filters immediately improves airflow capability. Every air conditioner depends on unrestricted airflow to operate correctly without overheating.
A professional technician also inspects the frame and housing for filters to ensure a proper airtight fit using correctly sized and installed filters to promote proper circulation through the system and your living space.
Check Thermostat Settings and Placement
HVAC professionals test thermostat calibration and function. Sometimes, recalibration fixes the problem, but in some cases, it is necessary to replace a defective thermostat. If the thermostat is improperly placed, a technician can reposition the device to a location where it can correctly sense indoor temperature.
Defrost Evaporator Coils
If you notice frozen evaporator coils, you should immediately turn off your HVAC for a few hours to let the ice melt completely. An HVAC technician can then inspect the system for refrigerant leaks or other problems causing the freezing and make proper repairs.
Inspect and Repair Refrigerant Levels
Only a certified cooling system technician should address leaking refrigerant issues. An HVAC expert can inspect the system to locate and repair leaks and then recharge the system with the proper chemical refrigerant to the appropriate level.
Address Electrical Issues
Only a licensed HVAC professional should address hazardous electrical issues. The technician can assess and repair faulty wiring or malfunctioning control panels.
Recommend Installing a Correctly Sized Unit
A cooling system professional can assess the cooling power needed for your home based on its size, condition, and configuration.
If you currently have an oversized unit or an undersized unit, an expert can provide recommendations for the correct sized unit for your property, which will be better suited to provide consistent and energy-efficient cooling power.
Call Leith Heating & Cooling for Complete HVAC Service
If you suspect you have AC short cycling issues, don’t wait until the situation becomes a bigger problem.
Leith Heating & Cooling, serving Mount Prospect, IL, and the surrounding areas, is a veteran and family-owned business committed to providing unmatched professional service.
As an Illinois Commerce Commission Certified energy-efficient installer and an EnergySmart trade ally with Nicor Gas and ComEd, we will ensure that your air conditioning system operates at its peak efficiency.
The friendly experts at Leith Heating & Cooling are here to provide complete HVAC service. Contact us online or call to schedule an AC short cycling repair service and bring your cooling system back up to peak performance. Learn more now.