Short cycling means your air conditioner or heater is starting up and shutting down prematurely. In other words, it is turning on and off too rapidly. Although often overlooked, AC short cycling can be a sign of a significant problem; addressing it promptly is as important as scheduling regular AC maintenance every year.
How Do I Know My AC Is Short Cycling?
An HVAC system normally runs in regular cycles that average 20 to 30 minutes. Therefore, it should turn on and off about two or three times an hour. It will run until the set temperature is reached and then turn off for a time. Short cycling is when the unit starts and stops in shorter increments.
This frequent turning on and off is an ineffective way to heat or cool your home. It is also extremely inefficient. The system will use more energy by turning on and off, so the problem can increase your utility bill. Short cycling also strains your air conditioning system, potentially leading to extensive damage and costly repairs. It is notorious for wearing out the compressor, which is the most expensive part of your HVAC system.
What Causes Short Cycling?
Different problems can cause AC short cycling. Some causes are easy to resolve, while others are more severe and can require extensive repairs. The most common reasons your AC or heater is short cycling include:
- Clogged Air Filter: The longer the air filter is in place, the more dirt, dust, and debris that collect on it. While this prevents contaminants from becoming airborne, the filter eventually becomes blocked, reducing airflow into the HVAC unit. This can result in the unit overheating, causing a safety switch to shut it down prematurely. The unit will turn on again once it cools. If the filter isn’t replaced, the process will repeat until the system breaks down.
- Refrigerant Leak: Short cycling can be a sign of low refrigerant. If this is the case, the system can’t properly absorb and transfer heat. The system will work much harder to reach the set temperature. The excess strain can cause the unit to overheat or malfunction, which can manifest as short cycling. Leaking refrigerant can also damage the HVAC components it touches.
- Frozen Coil: If the evaporator coil freezes, the system can overheat and shut down. An air conditioner cools a room when cold refrigerant passes through the coil and cools the air that is blown through it and into your home. An evaporator coil can become frozen for various reasons. Call an HVAC repair technician if shutting the system off for 24 hours doesn’t defrost the coil and resolve the issue.
- Malfunctioning Thermostat: If the thermostat isn’t properly calibrated, the system may start up and think it has reached the set temperature, which causes it to rapidly shut down. An issue with where your thermostat is placed can also cause AC short cycling. Thermostats should never be placed in direct sunlight or near heat-generating appliances. A mechanical or electrical issue is also a possibility.
- Air Duct Leak: Over time, air ducts can crack, tear, develop holes, or separate. Conditioned air can then leak and outside unconditioned air can enter the system, forcing it to work harder. Issues with performance and temperature control can cause it to quickly shut down.
- Electrical Problem: Short cycling can be a symptom of an electrical issue, such as a loose connection or a wiring connection that has corroded. It’s unsafe and potentially extremely dangerous to try to address an electrical problem yourself. Contact an HVAC technician to check for any issues they can safely fix.
- Undersized/Oversized AC Unit: If your air conditioner is too small or too large for your home, short cycling can occur. A unit that’s too large will cool your home too quickly and shut down before the cooling cycle is complete. A unit that is too small may not be powerful enough to reach the set temperature; it will strain itself until it overheats and shuts down.
How Can Short Cycling Be Fixed?
An AC service technician can fix short cycling by addressing the underlying cause. If left unchecked, the problem can damage other parts of your HVAC system and shorten its lifespan. You can also prevent AC short cycling by scheduling regular AC maintenance. A technician can catch problems early so they don’t take a toll on your system. When the unit starts to short cycle, call a professional who can promptly address the reason.
Contact Monarch Home Services
Our licensed and highly-trained AC and heating specialists can evaluate and repair your HVAC system if short cycling occurs. They also provide high-quality maintenance services to optimize performance and efficiency and prevent common issues. Whether you need a professional to address AC short cycling or provide a maintenance tune-up in your San Joaquin Valley home, call Monarch Home Services at (661) 215-6657.