Not all HVAC problems consist of screeching machinery or an AC that refuses to cool. Sometimes, the warning signs can be a lot more subtle. HVAC short cycling is a frequently overlooked issue that can end up making your whole system break down. To protect your system from short cycling, you need to understand what it is and why it happens.

What Is Short Cycling?

Short cycling occurs when your HVAC system is turning off and on repeatedly. It can be an issue with almost any type of system including air conditioners, heat pumps, furnaces, and electric heaters. This issue gets its name from the fact that your system won’t run through an entire heating or cooling cycle before it shuts down.

Of course, it’s perfectly normal for your system to occasionally switch on and only run for a little bit. This only becomes a problem when it is running on extremely short cycles. To count as short cycling, your system can only stay on for 10 minutes or less before shutting off. The other identifying factor of short cycling is that it happens over and over again. Instead of just running briefly during temperate weather and then staying off for hours, your unit will spend the whole day switching on and off again.

Common Causes of Short Cycling HVAC Systems

In some cases, short cycling means it’s time for maintenance. If you haven’t replaced your air filter in a long time, it can become very clogged. This makes it hard for fresh air to get pulled into the system. This could result in issues like heat getting trapped inside your AC system, so it constantly overheats and shuts off.

Short cycling can also indicate that something is broken somewhere in your system. Things like leaking refrigerant lines and failing low-pressure control switches can make your HVAC repeatedly turn on and off. Your service technician will also check your compressor if you’re dealing with short cycling. Your compressor regulates the running of your system, and if it’s failing, it can keep shutting off before your air is properly cooled.

In some cases, short cycling can be due to a problem with your thermostat, not your HVAC unit. Your thermostat repeatedly checks the temperature of your home to see whether or not your HVAC system should be running. If it’s calibrated incorrectly, it can result in inaccurate readings, resulting in it repeatedly turning your system off and on. The location of your thermostat can also impact short cycling. When your thermostat is too close to a vent, a blast of warm or cold air will trick it into thinking your system has done its job. However, when the air quits blowing, your thermostat will read the ambient temperature in the room and switch the HVAC system back on again.

Unfortunately, even brand-new, properly maintained, undamaged HVAC systems can short cycle. When a system is in good condition but keeps short cycling, this is usually a sign it is oversized. Finding the right HVAC size is a complex task that involves your technician considering everything from the number of windows to room shape to wall insulation. If they get something wrong, your improperly sized unit will struggle to run correctly. An oversized unit will quickly push a huge wave of cool air into your home. This will trick the thermostat into thinking everything is fine, so it will turn off your system. However, as the cooled air spreads through your home, things will get too warm too quickly, and your unit will turn on again.

Another factor to consider is your home itself. If your home has an abnormal amount of air escaping from the inside, your heated or cooled air can easily escape. Your system will turn on, adjust your temperature to the right level, and turn off. However, the treated air can then leak out through cracks or gaps under doors and/or around windows. The temperature will quickly change, and your HVAC system will have to turn back on again.

Why Is Short Cycling a Problem?

When your system short cycles, it fails to properly treat the air in your home. A good HVAC system is meant to do more than just cool or heat air. It’s also supposed to circulate air throughout your home and remove humidity. HVAC systems are designed to run continuously for several minutes. When your system only runs for a few minutes at a time, it doesn’t get enough time to ventilate and dehumidify your home. You’re more likely to end up dealing with musty air, and problems like mold and mildew can develop.

Furthermore, short cycling can make your energy bills a lot higher. Due to the way HVAC systems work, they use more power to get started than they do to keep running. If your system is turning on several times in a single hour, this ends up requiring far more power. Even if your system is very energy efficient, short cycling can end up wasting a lot of energy.

Short cycling is more than just an annoyance. Each time your system turns on, it takes a little extra effort to get all of the components moving. Repeatedly starting up the whole system puts far more wear and tear on it than it would get from running continuously. If you let it short cycle all the time, you’ll have a higher risk of damage. Short cycling is especially likely to damage the compressor, and replacing a burnt-out compressor is pricey and time-consuming.

How to Fix Short Cycling

The treatment for short cycling depends on what is causing it. In some cases, fixing it is as fast and simple as replacing a filter or patching a refrigerant leak. When your short cycling is just due to a temporary system malfunction, repairing the problem can be enough to stop the short cycling.

However, if your short cycling is due to an improperly sized unit, things are a little more complicated. While rearranging your vents or shifting your thermostat might help a little, short cycling will continue to be a problem. The only true solution to an oversized or undersized unit is to replace it. You will need to switch it out for a new HVAC unit that is properly sized and intended to be used for the size of your home.

If your HVAC system is having trouble, turn to At Your Service Heating & Cooling LLC. We’re one of the top Baltimore HVAC companies due to our stellar service and high-quality work. Our technicians can help with a variety of tasks including repairs, maintenance, and installation. We can help you figure out the problem behind your short cycling and recommend ways to solve it. To schedule an appointment with the At Your Service Heating & Cooling LLC team, give us a call today.

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