What to do When Your Furnace Stops Working

It’s a dark and cold afternoon. You notice it feels a bit chilly inside, so you dial up the thermostat expecting to feel some heat—except nothing happens. Oh no! When your furnace stops working, especially during the chilly months in Indiana, it can be a source of significant discomfort and concern. 

But what do you do when your furnace stops working? It starts by taking the steps to take to troubleshoot and potentially resolve the problem—or to know when it’s time to call in a professional. This guide will walk you through the essential steps to take when your furnace stops working, ensuring you stay warm and safe during Indiana’s colder seasons.

Step 1: Check Your Thermostat

Start with the simplest solution by checking your thermostat. Make sure it’s set to “heat” and the temperature is set higher than the current room temperature. 

You’ll also want to consider the type of thermostat you have. If it’s a programmable thermostat, ensure that it’s set correctly for the day and time. Sometimes, incorrect programming can prevent the furnace from turning on when you need it.

Battery replacement is another simple fix to consider. Many modern thermostats are battery-operated and may malfunction or not read temperatures accurately if the batteries are low. If the screen is blank or displaying a low-battery symbol, replace the batteries.

Finally, if your thermostat is a smart or Wi-Fi-connected model, troubleshoot that it’s properly connected to your home network. Loss of connectivity can disrupt the control over your heating system

Sometimes, a simple adjustment or battery replacement is all that’s needed.

Step 2: Inspect the Furnace Filter

Can a dirty filter stop your furnace from working? Absolutely! A dirty or clogged filter is a common culprit for furnace problems. 

Over time, furnace filters accumulate dust, pet hair, and other debris, which can significantly impede airflow. This restriction of air movement can lead to several issues:

  • Overheating: When airflow is obstructed, your furnace can overheat. Most modern furnaces have safety features that shut down the system to prevent damage in such cases. If your furnace is frequently turning off and on (short cycling), a dirty filter could be to blame.
  • Increased Energy Consumption: A furnace struggling with airflow must work harder to circulate warm air throughout your home. This not only leads to decreased efficiency but also increases your energy bills.
  • Poor Air Quality: A clogged filter is less effective at trapping contaminants, which means more dust and allergens circulating in your home. This can be particularly problematic for people with allergies or respiratory issues.
  • System Wear and Tear: Consistently running your furnace with a dirty filter can lead to premature wear and tear on the system. This might mean more frequent repairs and potentially a shorter lifespan for your furnace. This is also why preventative maintenance is so important!

The good news is that checking and replacing your furnace filter is a straightforward task. The filter is usually located near the blower unit and should slide out easily. When replacing the filter, ensure it’s the correct size and type for your furnace, and that it’s installed in the correct orientation (look for arrows on the filter’s frame indicating airflow direction).

Step 3: Ensure Proper Ventilation

Blocked or closed vents can lead to system imbalances that not only affect the comfort of your home but can also strain your furnace. Here’s what you need to do to make sure that you have good airflow:

  • Check All Vents and Registers: Walk through your home and examine all the vents and registers. Make sure they are open and not blocked by furniture, curtains, or rugs. Even partially blocked vents can disrupt the airflow, leading to cold spots in rooms and increased strain on your furnace.
  • Inspect Return Air Vents: Return air vents, which pull air back into the furnace for reheating, are equally important. Ensure they are not obstructed, as this can cause the furnace to work harder, reducing efficiency and potentially causing long-term damage.
  • Consider Room Usage: In some cases, you might be tempted to close vents in rarely used rooms to save energy. However, this can create pressure imbalances and make your furnace work harder to distribute air throughout your home. It’s generally better to keep all vents open for even heating and system balance.
  • Ductwork Inspection: If you’re still experiencing issues after checking the vents, there could be a problem with your ductwork, such as leaks, blockages, or poor design. This might require a professional inspection. Leaky ducts can lose a significant amount of heated air, reducing your system’s efficiency and increasing heating costs.
  • Routine Cleaning: Regularly cleaning your vents and ductwork can prevent dust and debris from accumulating, which might impede airflow and degrade indoor air quality.


Step 4: Look at the Circuit Breaker

Sometimes, the issue could be as straightforward as a tripped circuit breaker. Check your home’s electrical panel and reset the furnace’s circuit breaker if necessary. If the problem persists, call us to diagnose and repair the issue.

Step 5: Check the Furnace Flame

The color of the furnace flame can indicate various issues. It should be blue with a small yellow tip. If it’s mostly yellow, it could indicate a ventilation problem, which requires professional attention.

Step 6: Consider the Furnace’s Age

If your furnace is older, its efficiency could be diminishing. Older furnaces might need more frequent repairs or might be nearing the end of their lifecycle. Keep in mind that your furnace will likely last around 20 years

When to Call for Furnace Repair 

If the above steps don’t resolve the issue, or if you’re uncomfortable performing any of these checks, it’s time to call us at Area Sheet Metal Heating + Cooling. We can diagnose and fix more complex problems, making sure that your furnace operates safely and efficiently.

Even if you aren’t experiencing any furnace problems, consider joining our Discount Club. This is the best way to ensure that your furnace doesn’t unexpectedly break down in the cold. But if it does, Discount Club members get first priority for our services. Please reach out to us to learn more!