Furnace Troubleshooting Tips & Steps

Mom, dad, and daughter sitting on a couch trying to troubleshoot their furnace

While you enjoy the benefits of your furnace at home, you may experience problems such as your Furnace Making Loud Noises or your furnace not starting up. While you may consider calling a specialist to help you out, heating troubleshooting can be done by yourself.

With temperatures dropping, you want your furnace to operate optimally and make you comfortable at home. In this post, you’ll get furnace troubleshooting tips & steps to make your unit operate at optimal levels again.

How to diagnose furnace problems

Diagnosing furnace problems means analyzing and solving problems your furnace experiences. Common furnace problems most homeowners may experience include:

  • faulty thermostats,
  • furnace not heating room enough,
  • furnace making loud noises,
  • pilot control issues
  • ...and more

So what furnace troubleshooting steps should you take if you notice your furnace not operating as it normally does?

Steps on how to troubleshoot a furnace

Before you call a furnace repair specialist, go through this furnace troubleshooting guide to better understand the issue.

Step 1: Check if the thermostat is set correctly.

Ensure you double-check that it is set correctly. If you want it heating your home, it should be set to “heat” or “auto”.  This may seem like an obvious thing to do but the switch can easily move without you knowing, such as during dusting or cleaning.

Step 2: Check if your furnace filter deserves to be changed.

Most homeowners forget about checking and replacing their furnace filters. Filter-related issues are one of the major causes of most furnace breakdowns.

Your furnace filters are responsible for cleaning the air that flows through your system. They trap and prevent dirt and particles from damaging your system. When the filter is clogged with these substances, it can cause your unit to break down. If the filter is clogged, experts recommend you don’t clean it but instead replace it once each month.

Step 3: Inspect the battery if your unit uses batteries.

Most furnaces use electricity but some use batteries. Check if the battery is low and replace it.

Step 4: Inspect if your unit is receiving power.

If your unit uses electricity, switch it on and observe if it comes on. If not, try step 5.

Step 5: Inspect the circuit breaker.

Go to your system's breaker panel and locate the circuit that controls your unit. The breaker might be tripped. If so, turn it to the “on” position.

Step 6: Watch out for a code displayed.

Furnaces built from 1990 onwards have a small window that displays light. The light can not only inform you that the system has power, but it can also flash a code. If you want to know what the code means, open your system’s access panel and relay that information to a HVAC specialist.

Moncrief Heating & Air Conditioning provides heating and air conditioning in Atlanta as well as other residential and commercial HVAC services.