Check Out These Furnace Repair Tips Before Calling a Pro in Warner Robins, GA

It can feel nerve-racking when you have a frigid house in Warner Robins because your furnace won’t kick on.

Here’s the good news—you might be able to skip a furnace repair call with our troubleshooting instructions. You don’t need any special abilities. Plus, many of these fixes are economical (or even no cost).

This handbook might help you mend your furnace when it:

  • Won’t switch on
  • Won’t light
  • Won’t stay on

What to Do When You Need Furnace Repair

Gillman Heating and Air can be of service when you need a technician in Warner Robins.

Our equipment repair services include all makes and models. If it’s time for a new HVAC system, we also have furnace replacement and furnace installation.

If your heat has quit working, it might be due to a lack of yearly furnace maintenance. Normal service often helps us spot expensive problems before they can hurt your wallet, and could help your HVAC system run more efficiently.

During seasonal service, our certified pros will:

  • Observe your furnace
  • Make sure it’s operating accurately
  • Lubricate moving parts

A furnace that’s regularly serviced often lasts longer and runs more efficiently. That could help you save more on your monthly bill.

How to Troubleshoot Your Furnace

Ready to try patching up your furnace alone? Use our step-by-step instructions below.

Steps for Furnace Troubleshooting

Make Sure Your Thermostat is Working

The first step is to look at your thermostat, because it may not be requesting heat.

Digital Thermostat

  • Nothing on screen? Replace the batteries. If the display is still not working, you may need to replace the whole thing.
  • Make sure the switch is set to “heat,” not “off” or “cool.”
  • Is the program on the right day and set to “run”? You can also override it by using the up/down arrows and pressing the “hold” button. This will start the thermostat if your programming is not working.
  • Set the wanted temp 5 degrees warmer than the ambient temperature.
Digital Thermostat

Your furnace should kick on within a few minutes. If it stays off, look at its power supply by sliding the fan switch from “auto” to “on.” If the fan doesn’t run, your furnace may not have power.

Smart Thermostat

Do you have one of these well-known Wi-Fi thermostats? Find manufacturer-specific support and troubleshooting tips below.

Lennox Smart Thermostat

Contact us at 478-202-3076 if you still can’t get your smart thermostat to work.

Take a Look at Breakers and Switches

After troubleshooting your thermostat, you will want to check your breaker box and furnace switch.


  • Head to your home’s electrical panel, a gray metal box on the wall in your garage, basement or closet.
  • Make sure your hands and feet are dry.
  • Check the “furnace” or “heat” breaker and ensure it’s in the “on” position. It may be in the middle or “off” position if it’s tripped.
  • If the breaker has tripped, use one hand to change it to the “on” spot. If the breaker immediately trips again, don’t try again. Call us at 478-202-3076 straight away.

Furnace Switch

Regardless of age or manufacturer, your heater will have a regular light switch on or nearby it.

Not sure where to find your furnace? Investigate your:

  • Basement
  • Garage
  • Utility closet
  • Crawl space
  • Attic

Once you’ve located your furnace, take a look at the switch. It should be in the “on” position, with the switch flipped up. Your furnace could take up to five minutes to start if the switch was accidentally turned off.

Get a New Air Filter

When your furnace won’t operate correctly, an especially dirty or dusty air filter is often the culprit.

Here’s what can happen when you’re late for a filter replacement:

  • A dusty filter can trip your furnace’s breaker, shutting off power.
  • Blocked airflow can cause your furnace to overheat and shut down too hastily.
  • Your furnace could run more frequently (short cycling) and escalate your energy bills.
  • You may need to replace your furnace sooner because it is running more often.

How to Replace Your Furnace Filter

Your furnace’s air filter may be located in the blower compartment, attached filter case or wall-mounted return air grille.

Replacing a furnace filter

When putting in a new filter:

  1. Shut off your furnace.
  2. Remove the filter. Angle it toward the light. Can you see through it? If not, it’s time to replace it.
  3. Put in the new filter with the arrow pointing toward your furnace. Use a permanent marker on your furnace to list the airflow direction and filter size for next time.

Here’s how long filters often last:

  • Flat filters—one month
  • Pleated filters—three months
  • Washable filters—10 years

You should replace your filter more frequently if you have children, pets or allergies.

Look at the Condensate Pan

Condensate pans, or drain pains, carry the water your furnace removes from the air.

Is your furnace leaking water? Or maybe there’s excess water in the pan? Take these steps.

Pan with PVC Pipe/Drain

Start with a pan-cleaning tablet from a home improvement or hardware store. This will open up the pipe or drain.

Pan with Pump

Call us at 478-202-3076 if your float switch is “up” and there’s water in the pan. You will likely need to have your pump replaced.

Examine Inside Your HVAC System

Your furnace might be presenting an error code. Investigate inside the plastic window on the front or side of your furnace.

When your furnace is working correctly, the light should be an unblinking, colored light or blinking green light. It uses a flashing red light to disclose a fault code when something’s wrong.

Call us at 478-202-3076 if you’re getting an error code and we’ll fix the problem as fast as possible.

Get Rid of Gunk from Your Flame Sensor

Your flame sensor could be causing problems if your furnace tries to turn on but shuts off without pushing out heat.

A telltale sign is your furnace trying to start three times before a safety feature switches it off for about an hour.

You can clean this part at home if you feel comfortable opening your furnace. Or we can step in—just call 478-202-3076 for help.

Cleaning Your Flame Sensor

You’ll need:

  1. ¼” hex screwdriver or wrench
  2. Light-grit sandpaper, steel wool or emery cloth
  3. Paper towel

Before beginning, shut off power to your furnace through its breaker switch. Turn off the gas as well if the gas valve isn’t electric.

  • Lift off your furnace’s front panel and trace the wire to the flame sensor. It looks like a thin, bent rod.
  • Carefully unscrew the rod and lightly clean it using sandpaper, steel wool or emery cloth.
  • Brush off the rod with a paper towel.
  • Replace the sensor and put your furnace door back on.
  • Restore power to your equipment, which may move through a series of tests before turning on. If it doesn’t work again, you may need a new sensor or something else might be wrong. Call us at 478-202-3076 if this happens.

Reignite the Pilot Light

If you have an older furnace, its pilot light might be out. Look for guidance on the label on your furnace’s doors.

You can also take these steps:

  • Locate the switch on the bottom of your furnace labeled “pilot.”
  • Turn the switch to the “off” position.
  • Pause for at least five minutes to avoid starting a fire.
  • Return the switch to “pilot.”
  • Hold down the “reset” button as you bring a lit long lighter to the pilot light opening.
  • Release the “reset” button once you light your furnace.

Tried these steps twice but your pilot light won’t light or stay lit? Give us a call at 478-202-3076.

Check Other Gas Appliances

Do your other natural gas appliances work? If not, there may be an issue with your gas service. Or you may used up your propane.

We Can Fix Furnace Problems

Tried our troubleshooting guide but your furnace still won’t switch on?

Call us at 478-202-3076 or use our form to request an appointment today. We’ll visit your home and quickly fix the problem.