Does your furnace keep turning on and off before your house reaches the temperature set on the thermostat? This problem is known as short cycling. When working properly, a furnace should run for cycles that last anywhere from 10 to 15 minutes. If it’s short cycling, however, you’ll notice much shorter bursts of activity, and the system won’t stay on long enough to deliver the warm air you need. So, why is your furnace short cycling, and what can you do about it?
In this blog, we’ll explore the top causes of furnace short cycling and provide actionable tips to prevent it from happening in the future.
Top Causes of a Short Cycling Furnace
When your furnace runs for brief periods, shuts off, and then quickly restarts, it is considered to be “short cycling.” Because this issue can lead to a range of problems for your home and your wallet, it’s important to understand why a furnace short cycles in the first place. Here’s a look at the top factors behind this frustrating issue:
Dirty Air Filters
One of the most common reasons for a furnace to short cycle is a dirty air filter. A clogged air filter restricts airflow, causing your furnace to work harder than it should. When air can’t pass through the filter properly, the furnace can overheat, triggering the safety features that shut down the system to prevent damage. If this happens repeatedly, the furnace will keep turning on and off, resulting in short cycling.
To prevent this, make sure to replace your air filters every one to three months, especially during the peak heating season. A clean filter ensures that your furnace can work properly, supplying warm air throughout your home without unnecessary interruptions.
Incorrect Thermostat Placement or Malfunction
The thermostat is the brain of your heating system, so it’s important that it’s functioning accurately and placed in the right spot. If your thermostat is located near a heat source, like a fireplace or direct sunlight, it can misinterpret the room’s temperature and cause the furnace to shut off too soon.
To ensure your thermostat is doing its job, avoid placing it in areas that don’t accurately reflect the overall temperature of your home. Also, consider upgrading to a programmable or smart thermostat that can provide more accurate and efficient control over your heating cycle.
An Oversized Furnace
Having a furnace that’s too large for your home may sound like a good thing, but it can actually cause more harm than good. An oversized furnace heats up the space too quickly, leading to an inefficient and rapid heating cycle. This causes the furnace to shut off prematurely before your home is evenly warmed.
If you’re noticing uneven heating or frequent short cycling, it may be time to assess whether your furnace is the right size for your home. A properly sized furnace is essential for efficient heating.
Overheating Issues
If your furnace is short cycling, it may be overheating. Overheating can occur due to restricted airflow, as mentioned earlier, but it can also happen if there’s a buildup of dust and debris within the furnace. When the system overheats, it triggers the safety features that cause the furnace to shut off abruptly, only to cycle back on again once it cools down.
Regular cleaning and maintenance can go a long way in preventing overheating. Make sure to keep the area around your furnace clear of any debris, and schedule professional furnace maintenance to ensure your system is running smoothly.
Malfunctioning Blower Motor
The blower motor is responsible for circulating warm air throughout your home. If the blower motor isn’t working properly, the furnace may not be able to distribute warm air effectively, leading to a short cycling furnace. In some cases, the blower motor may overheat or fail entirely, causing the furnace to shut off. If you suspect an issue with the blower motor, it’s best to call a professional technician for a thorough inspection and any necessary repairs.
Dirty Flame Sensor
The flame sensor is a safety component that detects whether the burners are lit. If the sensor is dirty or malfunctioning, it may not detect the flame correctly, causing the furnace to short cycle. Cleaning the flame sensor can often resolve this issue, but it’s a delicate task best handled by a professional technician. Regular maintenance will help keep the flame sensor, as well as other critical furnace parts, in good working condition.
How to Prevent Furnace Short Cycling
Preventing furnace short cycling starts with proactive maintenance and a few simple steps to ensure your heating system is in top condition.
- Schedule Regular Furnace Maintenance: Routine maintenance is one of the best ways to prevent short cycling and other common furnace issues. During a maintenance visit, a technician will inspect, clean, and tune up your furnace, addressing any potential problems before they become major issues.
- Change Your Air Filters: Make it a habit to change your air filters regularly, about every 1-3 months. By keeping your filters clean, you’ll help maintain proper airflow and prevent overheating.
- Evaluate Your Thermostat Placement: Ensure your thermostat is installed in a central location away from direct sunlight, heating vents, or other sources of heat. This will give you a more accurate reading of your home’s temperature and prevent your furnace from cycling on and off unnecessarily.
- Address Issues Promptly: If you notice something isn’t quite right with your furnace’s performance, don’t ignore it! Addressing the issue promptly can prevent short cycling and further damage to your heating system. Whether it’s a dirty flame sensor or a malfunctioning blower motor, taking action sooner rather than later can save you from costly furnace repairs down the line.
Find Out Why Your Furnace Is Short Cycling
Short cycling is a common issue that can affect the efficiency and longevity of your furnace. By understanding what causes a furnace to short cycle and implementing the preventive measures mentioned above, you can help your heating system run smoothly and keep your home cozy throughout the winter months.
If your furnace is short cycling or if you’re experiencing other issues with your heating system, connect with the professionals at H.J. Faust, Inc. Our team is dedicated to providing high-quality furnace repairs in Burlington, WI, and the surrounding areas and will keep your system in peak condition. Contact us today for reliable service and a warm, comfortable home all season long!
