When your furnace won’t start, doing your own furnace repair in Hodgenville, Kentucky, can feel pretty overwhelming.

Figuring out a furnace-related problem might feel like a complicated job when your heat won’t power on. But it doesn’t have to be like that.

There are a number of time-saving, low-cost fixes you can do by yourself to skip a furnace repair call.

If your furnace won’t turn on, won’t stay on or won’t ignite, try the troubleshooting list below before calling an HVAC professional.

If you find you need help from a heating and cooling expert and live in Hodgenville, Phelps Heating & Cooling, Inc. can help you. We can repair most brands of heating systems and also provide emergency furnace repair.

If you’re ready for a new heating system, we also provide furnace installation.

While you’re in touch with us, think over a routine furnace maintenance plan that might help you avoid problems in the future. We can tell you how regularly your furnace should be examined by one of our professionals.

Follow our easy guide below to get to work on troubleshooting your furnace. Most of these steps don’t require mechanical know-how.

Furnace Repair Checklist

1. Check the Thermostat

First, make sure your thermostat is telling your furnace to ignite.

Digital Thermostat

Change the batteries if the screen is blank. If the digital screen is jumbled, the thermostat may need to be replaced.

Make sure the switch is set to “heat” instead of “off” or “cool.”

Ensure the program is showing the correct day and time and is set to “run.” If you’re having a hard time overriding the program, set the temperature by using the up/down arrows and press the “hold” button. This will cause the furnace to start if thermostat programming is causing a problem.

Increase the temperature setting to 5 degrees warmer than the room temperature.

If your furnace hasn’t kicked on within a couple minutes, make sure it has power by toggling the fan switch from “auto” to “on.” If the fan doesn’t begin to run, your furnace could be without power.

Smart Thermostat

If you have a smart thermostat—like one made by Nest, Ecobee, Lux, Honeywell or Bosch—troubleshooting is very model-specific. Check the manufacturer’s website for help. If you still can’t get your Wi-Fi thermostat to work, call us at 270-358-3167 for heating and cooling service.

2. Examine Breakers and Switches

Next, you will need to check if your breaker and furnace switch are on.

Find your house’s main electrical panel. If you have no idea where it is, search for a gray metal box in your basement, garage or closet.

Make sure your hands and feet are dry before touching the panel or breakers.

Look for the breaker labeled “furnace” or “heat,” and make sure it’s switched “on.” If the breaker has tripped, it will be in the middle or “off” position.

Using one hand, firmly switch the breaker to the “on” position. If the breaker immediately trips and pops back to “off,” don’t try to reset it and get in touch with a professional from Phelps Heating & Cooling, Inc. at 270-358-3167 right away.

It doesn’t matter how old your furnace is or what brand it is, it has at least one standard wall switch located on or by it.

Make sure the switch is flipped up in the “on” position. If it was turned off, it could take your furnace up to five minutes to ignite. (If you don’t know where to find your furnace, check your basement, garage or utility closet. It could also be in a crawl space or attic.)

3. Replace the Air Filter

When it comes to furnace breakdown, a filthy, clogged air filter is often to blame.

If your filter is too dirty:

  • Your furnace won’t be able to stay on, or it could overheat from reduced airflow.
  • Your energy bills could be higher because your furnace is turning on more often.
  • Your furnace could fail sooner than it should because a dirty filter causes it to work overtime.
  • Your furnace can lose power if an excessively dirty filter causes the breaker to trip.

Depending on what type of furnace you have, your air filter can be found inside the blower compartment of your furnace, an attached filter case or wall-mounted return air grille.

To replace your filter:

  1. Turn off your furnace.
  2. Pull out the filter and angle it toward the light. If you can’t see light through it, get a new one.
  3. Put in the new filter with the arrow pointing toward the furnace to avoid damage.

Flat filters should be replaced once a month, while pleated filters should last about three months. You can also use a washable filter that will last about 10 years. If you have children or pets, you may have to change your filter more often.

To make the process go more quickly in the future, use a permanent marker on your furnace housing or ductwork to list the airflow direction and filter size.

4. Inspect the Condensate Pan

Also known as drain pans, condensate pans hold water your furnace pulls from the air.

If water is dripping out of your furnace or its pan has standing water in it, follow these steps.

  • If your pan has a drain (look for a PVC pipe), check that it’s clear. If it needs to be drained, use a special pan-cleaning tablet you can get at home improvement or hardware stores.
  • If your pan has a pump, inspect the float switch. If the switch is stuck “up” with water in the pan, contact us at 270-358-3167, because you will probably need a new pump.

5. Check for Furnace Error Codes

If malfunctions keep on happening, look inside your furnace’s plastic window to check the status of the blower motor. Depending on the model, the light could also be fixed on the outside of your furnace.

If you see anything except a steady, colored light or blinking green light, call us at 270-358-3167 for HVAC service. Your furnace may be emitting an error code that requires professional service.

6. Clean the Flame Sensor

If your furnace tries to start but switches off without distributing heat, a dirty flame sensor could be at fault. When this takes place, your furnace will make an attempt to start three times before a safety feature powers it down for about an hour.

If you feel comfortable with opening up your furnace, cleaning your flame sensor is something you can do yourself. Or, one of our heating service experts can do it for you.

If you want to clean the sensor yourself, you’ll need:

  • A 1/4” hex screwdriver or wrench
  • Piece of light grit sandpaper, steel wool or emery cloth
  • A dry, clean paper towel

Next:

  • Disable the furnace’s power by using its wall switch or breaker. If your gas valve is not electric, you will need to shut off the gas as well.
  • Remove the furnace’s front panel and track the wire to the flame sensor.
  • Unscrew the rod and use your sandpaper, steel wool or emery cloth to gently rub the metal rod.
  • Wipe off the rod with a paper towel.
  • Remount the sensor.
  • Replace the furnace doors.
  • Turn the furnace’s power back on. It might run through a sequence of checks before proceeding with normal operation. If your furnace doesn’t ignite, the sensor may need to be replaced or something else might be wrong. If this happens, contact us at 270-358-3167 for heating and cooling repair assistance.

7. Relight the Pilot Light

If you are using an older furnace, the pilot light could be turned off. To relight it, find the instructions on a label on your furnace, or follow these steps.

  • Locate the switch on the bottom of your furnace labeled “pilot,” “on” and “off.”
  • Turn the switch to the “off” position.
  • Wait at least five minutes to avoid possibly sparking a fire.
  • Turn the knob to “pilot.”
  • Hold down the “reset” button as you bring the flame of a long lighter to the pilot light opening.
  • Release the “reset” button once the pilot light is lit.

If you have followed the instructions twice and the pilot light still won’t light or stay lit, call us at 270-358-3167 for furnace service.

Check Your Fuel Source

Try using another gas appliance. If it doesn’t work, your natural gas service could be turned off, or you could be out of propane.

We Can Help with HVAC Repair

Followed our troubleshooting guide but your furnace still won’t work?

Call us today at 270-358-3167 or contact us online. We’ll come out and figure out the problem.

Request Service