122 N 2nd St, Rockford, IL 61107 
Have you ever thought to yourself, “Why is my furnace still running?” If you have, you’re not alone. It’s not uncommon for your furnace to run more frequently, especially when it’s colder than normal outside. However, it can be hard to know if your furnace is running normally or if it’s struggling to keep up with your heating demands.
While there isn’t one set amount of time your furnace should run, there are several different things that can affect its run time. In this blog, we’re covering what to expect during a typical furnace cycle, what may affect how long your furnace runs, and signs it may be running too long or not long enough.
What does a normal furnace cycle look like?
When talking about a furnace cycle, we’re referring to when your thermostat detects that your home’s indoor temperature is below your set temperature. Once it does, your furnace then turns on and runs until your home reaches your desired temperature before shutting off.
When it comes to run times, the typical furnace cycle is about 10-15 minutes. However, this isn’t a fixed timeframe because there are several different things that can affect how long your furnace actually runs. You may notice it cycles through a couple of times in an hour, which can be completely normal. But if you’re experiencing especially cold weather, it may run longer or turn on more often.
You don’t need to worry about actually timing your furnace cycles. Instead, you want to see if your furnace is actually reaching and maintaining your set indoor temperature consistently. If it feels like your furnace is constantly running or shutting off too soon, there may be an underlying issue with your HVAC system that needs to be addressed by an HVAC professional like Allen Heating, Cooling, and Plumbing.
What affects how long your furnace runs?
There are several different factors that can affect how long your furnace runs, including:
- Outdoor temperatures
- Thermostat settings
- Make, model, and age of your unit
- Insulation
Outdoor temperatures
When it’s especially cold outside, your furnace may have a harder time keeping up. Your home may lose heat quicker than you think, so it’s harder for your HVAC system to maintain a consistent temperature. On the other hand, if we’re experiencing a mild Midwestern winter, your furnace may not run as much as you’re used to.
Thermostat settings
Sometimes, your thermostat’s set temperature may be affecting how long your furnace runs. Be mindful of what your thermostat is set at because if it’s set at a higher temperature, it may take your furnace more time to reach and maintain your desired setting. For example, if your thermostat is set to 76°F, your furnace may run longer or more frequently than if it were set to 72°F.
Make, model, and age of your unit
These factors, along with its maintenance schedule, size, and overall condition, can affect your run time as well. If your unit is oversized, it may heat your home too quickly and shut off before completing a normal cycle. If it’s undersized, it may run for longer periods of time as it struggles to meet your heating demands.
Insulation
Your home’s insulation also plays a role in how long your furnace may run. If you have poor insulation or gaps that allow heated air to escape, your home may lose heat faster and feel colder. Leaks in your air ducts can also lead to heat loss. Your furnace may continue to run longer or more frequently to make up for the lost heat.
Your furnace may run longer or more frequently depending on these factors, but it should still be able to keep your home at a consistent and comfortable temperature.
When should I call a professional?
While some variation in your system’s run time is normal, there are times when short cycling or running too long may point to an underlying problem. If your furnace seems to be running constantly but still struggles to reach or maintain the temperature set on your thermostat, your system may not be able to keep up with your home’s heating demands.
At the same time, your furnace may be short cyling if it repeatedly turns on and shuts off after only a few minutes without completely heating your home. You can check your thermostat and air filter to see if there may be a problem with the settings or if a dirty air filter is restricting airflow.
If the problem persists or you notice a sudden change in how long or how frequently your furnace runs, it’s time to call an HVAC professional like Allen Heating, Cooling, and Plumbing. We can thoroughly inspect your furnace to see if there are any underlying problems that need to be addressed.
Contact Allen Heating, Cooling, and Plumbing today for all of your plumbing, heating, and cooling needs
If you’re looking for an honest and fair local HVAC and plumbing company, Allen Heating, Cooling, and Plumbing is here to help. We offer a comprehensive 19-point furnace Clean & Check to identify any issues and thoroughly clean your unit, so it’s ready for the upcoming season.
Our experienced techs provide high-quality services, including installation, annual maintenance, emergency repairs, and more. We carry top-of-the-line products from the industry’s best brands, Honeywell, American Standard, Mitsubishi, and more. We are also a Bryant® Dealer. Our technicians can make expert recommendations for tailored indoor comfort at a fair, affordable price.
With over 29 years of service under our belt, we’re well-equipped to handle all of your heating, cooling, ventilation, and plumbing needs in northern Illinois. So call our office today at 815-298-8020 to schedule your next service appointment.
