If your HVAC system is turning on and off in quick successions, it may be due to short cycling. The AC system kicks in to maintain a cool temperature when your home becomes too warm. The unit goes through cycles or the process to reach a preset temperature and then shuts off to repeat the cycle.
The average HVAC cycle lasts about 20 minutes, and if it goes through the cycle quicker than this, short cycling may be the culprit. Over time, it causes a spike in energy bills and repair costs. So, any disruption in this cycle is an indication to call your HVAC contractor for an inspection.
What Causes Short Cycling in the HVAC System?
The HVAC system works by powering up a compressor that runs until it meets the temperature set on the thermostat. The unit powers down the compressor soon after that. So, if the compressor in your unit stops prematurely before ending the cooling cycle, it is a symptom of a bigger problem.
To troubleshoot the issue, you have to know about its causes first. Some conditions leading to short cycling are:
The refrigerant flows through the HVAC system to absorb indoor heat and cool down your home. Low levels of refrigerant in the unit produce extra stress on the HVAC system, and it triggers the lower pressure control of the compressor and shuts it off.
As the pressure increases, it triggers your system to restart and cause short cycling. Low refrigerant levels can also freeze the coils and lead to bigger issues down the road. Before it happens, call your HVAC contractor to find the leak and repair it immediately.
The Unit Is Oversized
In the case of an HVAC system, the bigger is not always a better option. Investing in an incorrect size for your building causes short cycling. If your unit is too big for the building, it will blast cool air and shut off before dehumidifying properly.
As a result, your house may have several hot and cold spots. Plus, your electricity bills may also go higher than expected. Hence, work with a trusted contractor to find the right size according to your cooling or heating needs.
Clogged or Dirty Air Filters
Depending on the conditions of your HVAC, you should clean or replace air filters regularly. If the screen gets dirty, it forces the unit to work harder and consume more electricity. Allergens like dust particles, detritus, or dirt can clog the air filters and make your HVAC use more pressure to compensate for the reduced airflow.
Also, it affects the components responsible for the functioning of the blower and compressor in the unit. The increased pressure on these components causes short cycling and a complete breakdown with hefty repair costs.
Dirty or Frozen Evaporator Coil
If the evaporator coils eat ice, it can also cause short cycling in your HVAC system. Evaporator coils are responsible for removing hot air from your home. And if they are frozen, it makes the unit work harder. It is a matter of negligence in HVAC maintenance, though.
For curing the problem, you can shut down the unit and let it thaw before rerunning it. However, if the coil freezes again, give your HVAC contractor a call to assess and repair the issue.
Faulty Wiring or Electrical Issues
Corroded electrical connections and loose wiring can also trigger short cycling in an HVAC system. Due to these issues, the heat pump or air conditioner in the unit loses power and cannot turn on or off at the right time. Instead of fixing the issue yourself, rely on experts to handle it properly.
What Should You Do to Cure Short Cycling?
If you neglect the problem of short cycling for a longer time, you may put your entire HVAC system at risk. Short cycling adds strain to the unit and wears out various components. Since it is a symptom of a deeper problem, the faulty part can cause further damage and ultimately burn out the system. Remember, changing a compressor can be a significant expense you can avoid with timely maintenance.
Do You Need to Replace the HVAC System Due to Short Cycling?
In most cases, the problem causing short cycling may be simple, like a clogged air filter or faulty thermostat position. However, if the condition is worse than these, you may need to replace the system and invest in an energy-efficient unit that will cost you less and cool your house quickly.
You can even prevent this issue with yearly servicing and inspection by a certified mechanic.