When the furnace kicks on during cold winter nights, it’s like a warm hug for your home. The comforting rush of heated air lets you know your heating system is doing its job, keeping the cold at bay so your family can relax in comfort. But what happens when that familiar sound doesn’t stop? If your furnace is running constantly, it could be a sign of a problem that needs your attention.
We’ll look at five common reasons your furnace might be running nonstop and offer tips to help you address the issue.
What Causes a Furnace to Run Constantly?
Your furnace is designed to heat your home efficiently, cycling on and off as needed to maintain your desired temperature. When it doesn’t shut off, it’s often a sign that something isn’t working as it should. Below are five reasons your furnace might be running continuously, plus practical advice on how to fix the problem.
1. Thermostat Problems
Your thermostat is the brain of your heating system, controlling when the furnace should start and stop. If something’s wrong with your thermostat, your furnace might run continuously.
- Incorrect thermostat settings: Double-check that your thermostat is set to “auto.” The “on” setting keeps the furnace fan running non-stop, even when the burner isn’t heating air.
- Damaged or faulty wiring: Corroded thermostat wires or poor connections can interfere with your thermostat’s signals, leading to constant operation.
- Old or faulty components: An outdated or broken thermostat might misread the indoor temperature, keeping the furnace running longer than needed.
What you can do: Since thermostat troubles could be what causes a furnace to run constantly, start by inspecting your thermostat settings and location. If it’s near drafty windows or direct sunlight, it could be reading the temperature incorrectly. For wiring or component issues, it’s best to call a technician.
2. Dirty Air Filters
A dirty air filter is one of the most common culprits behind a constantly running furnace. When the filter becomes clogged with dust and debris, it restricts airflow through the system, forcing the furnace to work harder to heat your home.
Some signs your air filter might need attention include:
- Reduced airflow: Less air comes through your vents, making it harder to maintain the desired temperature.
- Uneven heating: Certain rooms might feel warmer or cooler than others.
- Overheating: Restricted airflow can cause the furnace’s burner to overheat and shut off, leaving the blower running nonstop.
What you can do: Since a dirty air filter could be why your furnace runs constantly, make checking it a priority. Inspect your air filter at least once a month during the colder months. If it looks dirty, replace it with a new one to improve proper airflow and system efficiency.
3. Heat Loss Due to Poor Insulation
If your furnace runs constantly, it might be because your home is losing heat faster than the system can replace it. Heat loss often occurs because of poor insulation or leaks in your home’s ductwork.
Here are a few ways heat loss can affect your furnace:
- Drafty areas: Gaps around windows and doors allow cold air to seep in and warm air to escape, making your furnace run longer to compensate.
- Leaky ductwork: Cracks or holes in your ducts let heated air escape before it reaches your living areas.
- Inadequate insulation: Without proper insulation in your walls, attic, or crawl spaces, your home loses heat quickly, causing the furnace to cycle more frequently.
What you can do: Seal gaps around windows and doors using weatherstripping or caulking, and consider adding more insulation where needed. Have a professional inspect your ductwork for leaks to improve the efficiency of your heating system.
4. Blower Motor or Fan Switch Problems
Your furnace’s blower motor and fan switch play a critical role in circulating warm air throughout your home. If these components aren’t working correctly, your furnace might keep running even when it’s not heating.
Common issues with the blower or fan include:
- Incorrect fan switch setting: If the fan switch is set to “on,” the blower will run continuously. Switching it to “auto” guarantees that it only runs during a heating cycle.
- Blower motor problems: A failing motor might struggle to push enough air through the system, leading to inefficient heating and extended run times.
- Unusual noises: Loud or unusual sounds from the blower motor could indicate worn-out parts that need to be replaced.
What you can do: Wondering if a blower motor or fan switch is why your furnace runs constantly? Start by checking the fan switch on your thermostat. If the problem persists, a professional technician can inspect the motor and make any necessary repairs.
5. An Aging or Improperly Sized Furnace
Sometimes, the issue isn’t a malfunction but the furnace itself. If your furnace is too old or not the right size for your home, it may struggle to keep up with your heating needs, leading to constant operation.
Here’s how this can happen:
- Undersized furnace: If the furnace isn’t powerful enough for your home’s square footage, it will run nonstop, trying (and failing) to reach the set temperature.
- Aging furnace: Older furnaces become less efficient over time. A system that’s more than 15 years old might run continuously simply because it can no longer heat as effectively.
- Frequent repairs: If your furnace needs constant maintenance or seems to break down often, it’s likely nearing the end of its lifespan.
What you can do: If your furnace is old or struggling to meet your home’s heating demands, it might be time to consider an upgrade. A professional can help you choose a properly sized, energy-efficient unit that meets your needs.
How Long Is Too Long for a Furnace to Run?
During extremely cold weather, it’s normal for your furnace to run for longer periods. However, it should still cycle off periodically. If your furnace runs for hours at a time without shutting off, it’s time to investigate what’s causing the problem.
What Should You Do Next?
If your furnace is running nonstop, don’t ignore the warning signs. Strange noises, uneven heating, or skyrocketing energy bills all point to issues that need attention. When left unchecked, these problems can escalate, costing you more money and comfort in the long run.
Falls Heating & Cooling is here to help. Our skilled technicians offer top-notch furnace repair in Akron, OH, and the nearby areas.
Ready to Fix Your Constantly Running Furnace?
So, what causes a furnace to run constantly? Ultimately, the issue can stem from a variety of factors, including incorrect thermostat settings, poor insulation leading to heat loss, and dirty air filters that restrict airflow.
If your furnace runs continuously, it’s a sign that something isn’t right. At Falls Heating & Cooling, we’ve been helping homeowners in the Akron area since 1986. Our technicians can diagnose furnace problems, repair faulty components, and recommend solutions that will keep your home warm and efficient all winter long.
Contact us today to schedule your furnace check-up in Akron, OH, or one of the surrounding communities. Your family’s comfort depends on it!
