5 Common Reasons We Get Called When a Furnace Runs, but Doesn’t Heat
When it’s freezing outside, there’s nothing more frustrating than hearing your furnace running nonstop while your home still feels chilly. Many Central Illinois homeowners assume this means their furnace is about to fail, but that’s not always the case.
In reality, there are several common reasons your heating system may be working without delivering the comfort you expect. Some are simple fixes. Others signal it’s time to call in a professional.
Below are the most common causes we see this time of year and how to know when it’s time for heating repair.
1. Restricted Airflow in Your Home
Even if your furnace is running properly, it can’t heat your home effectively without proper airflow.
Common airflow issues include:
- Closed or blocked supply vents
- Furniture or rugs covering floor vents
- Dirty air filters are restricting circulation
When airflow is restricted, warm air never reaches certain rooms, leading to cold spots and uneven heating.
What to do:
Make sure all vents are open and clear, and replace your air filter regularly during the winter months.
2. Your Furnace Is Sized or Set Up for Mild Weather
During extreme cold snaps, your furnace may struggle to keep up if:
- The system is undersized for your home
- The furnace was not properly set up or adjusted
- Your home has older insulation or air leaks
In these cases, the system runs constantly but can’t quite reach the thermostat setting.
What to do:
If your home never seems to warm up during colder stretches, a professional evaluation can determine whether your system is operating as efficiently as possible, or if a different system is the smart choice for your home.
3. Thermostat or Sensor Issues
Sometimes the problem isn’t the furnace at all.
Possible thermostat issues include:
- Incorrect placement near drafts or cold walls
- Low batteries causing inconsistent readings
- Calibration issues causing short cycling or uneven heating
What to do:
Check thermostat batteries and settings. If problems persist, a technician can verify proper operation.
4. Ductwork Problems or Heat Loss
Leaky or poorly insulated ductwork can cause warm air to escape before it reaches your living spaces.
Signs of duct issues include:
- Certain rooms never warming up
- Weak airflow from vents
- Higher heating bills with less comfort
What to do:
Ductwork inspections can identify leaks or airflow restrictions that the furnace alone cannot overcome.
5. Mechanical Issues Inside the Furnace
If your furnace is running but not producing enough heat, internal components may be failing.
Common winter repair issues include:
- Failing blower motors
- Malfunctioning heat exchangers
- Ignition or burner problems
These issues often worsen over time and should be addressed quickly to avoid a full breakdown.
When to Call for Heating Repair
If your furnace is running constantly, rooms feel unevenly heated, or your comfort has dropped noticeably, it’s best to have a professional take a look. Addressing the issue early can prevent emergency repairs and keep your home comfortable during the coldest weeks of winter.
Call Lanz for Reliable Heating Repair
At Lanz, Inc., we provide fast diagnosis and dependable heating repair for homes in Central Illinois. Whether your furnace can’t keep up or something just doesn’t feel right, our team is ready to help.
Call for service 217-394-1380 or contact us online.
