Short Cycling: Why It’s Bad News For An Air Conditioner

Sep 8, 2020

Ah, the familiar whirring and whizzing of your air conditioner; this sound is one you hear frequently during the summer months. But what if you hear it too frequently? Buying an AC unit is an important investment for your home – you want to protect it at all costs. Why does it keep shutting off and on? This is called short cycling, and it can send your AC unit to an early grave. It happens when your system powers down before it can reach the optimal temperature and humidity level. Short cycling wastes energy, increases the need for repairs, and lowers performance. What causes it, and how do you fix it?

A regular AC cycle lasts about 15 minutes, typically occurring 2 or 3 times an hour. It begins when the thermostat requests cold air. The compressor activates until it reaches the optimal temperature and moisture level. When the thermostat registers the desired temperature, the compressor will shut down. It only turns on again when it needs to maintain the optimal level of cooling. With short cycling, your compressor will turn off and on in under 10 minutes. Then, it turns back on just a few minutes later. This makes a significant difference in your energy bills because an AC system consumes the most power during the start-up cycle. Even though your unit still cools the air, it doesn’t have time to reach all the rooms in your house. That means you’ll have reduced performance for a greater cost. And if this problem goes unrepaired, you’ll need to replace your AC system much sooner than you’d like. If you suspect that your compressor is short cycling, it’s time to find out why. How does it happen? There are a few different culprits:

Sometimes, short cycling is caused by a clogged filter. A build-up of dirt and hair will put additional strain on the fan, making the system overheat and shut down before its cycle ends. It’s important to change your AC filter every 30-90 days to prevent this issue. Another reason could be that your AC is leaking refrigerant, an issue that will require a repair. It can make the compressor overheat, so you’ll need a technician to seal the leak ASAP. Short cycling can also occur when a thermostat is malfunctioning or reading the wrong temperature – this signals your AC to shut down before it has completed its cycle. Sometimes, the evaporator coils freeze. This component removes the hot air from your home. Your coils need to be defrosted before they can resume regular functioning. Houses with AC systems that are too large for them can be the cause of short cycling; the oversized unit cools the house too quickly, which signals the thermostat to shut down before the cycle has been completed. When this happens, energy bills skyrocket and humidity remains high in your home. Unfortunately, you’ll need to replace your AC to fix this issue, since you’ll need a properly-sized unit. 

Finally, a short cycle can also be caused by a leaky ventilation system. If cold air leaks through your ductwork, your compressor won’t be able to complete its cooling cycle. There are multiple causes behind short cycling, and the only way to trace the source is with the help of an HVAC technician.

Homeowners might feel tempted to ignore the signs of short cycling. After all, their AC unit still cools their home, so what’s the problem? But short cycling is one of the worst things that can happen to your air conditioner. It will substantially increase the cost of your energy bill. The strain it puts on your system means that parts will break down, causing you to have to call a professional to repair it. A short cycling AC won’t effectively cool your entire home and will shorten the life of your unit. Rather than lasting 15-20 years, your system might need to be replaced much sooner. When you consider the size of that expense, having it repaired won’t seem as costly. You can prevent short cycling by having your AC unit regularly maintained by a trusted HVAC technician. 

Short cycling raises your cooling costs and damages your AC unit. The earlier that you take action, the better; it’ll prevent any further damage to your system. With the help of an HVAC professional, you can save your unit from unnecessary damage, and improve how cool your home is. Provincial Heating and Cooling offers air conditioner repair in Winnipeg. You can give us a call, and we’ll determine the cause behind your short cycling. 


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