furnace repair

Opelika is Getting Cold, but My Furnace Wont Turn On

Troubleshooting your furnace might feel like a daunting task when your heat won’t work. But it doesn’t have to be like that.

There are several fast, reasonable fixes you can do by yourself to avoid 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 contacting an HVAC professional.

If you find you need help from an expert and live in Opelika, Farnell Mechanical, Inc. can help you. We repair most brands of heating systems.

If it’s time for a new heating system, we also offer furnace replacement in Opelika.

While you’re talking with us, think over a regular furnace maintenance plan from Farnell Mechanical, Inc. that may help you avoid breakdowns in the future. We can tell you how regularly your furnace should be inspected by one of our NATE-certified professionals.

Follow our easy guide below to get started on troubleshooting your furnace. Most of these steps don’t require mechanical skills.

Steps for Furnace Troubleshooting

Check the Thermostat

To begin, make sure your thermostat is instructing your furnace to ignite.

If you have a 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” as opposed to “off” or “cool.”
  • Ensure the program is displaying 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 an issue.
  • Increase the temperature setting to 5 degrees warmer than the room temperature.
Digital Thermostat

If your furnace hasn’t turned on within few minutes, make sure it has power by toggling the fan switch from “auto” to “on.” If the fan doesn’t start, your furnace may not have power.

If you have a smart thermostat—like one made by Nest, Ecobee, Lux, Honeywell or Bosch—troubleshooting is very model-specific. Refer to the manufacturer’s website for help. If you still can’t get your Wi-Fi thermostat to work, contact us for assistance.

Lennox Smart Thermostat

Examine Breakers and Switches

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

  • Locate your house’s main electrical panel. If you don’t know where it is, keep an eye out 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,” leave it alone and contact a professional from Farnell Mechanical, Inc. at 334-245-4748 right away.

No matter your furnace’s age or brand, it has at least one standard wall switch located on or close to it.

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

Replace Your Furnace’s Air Filter

When it comes to furnace breakdowns, a dirty, clogged air filter is regularly to blame.

If your filter is too dirty:

  • Your furnace won’t stay on, or it could overheat from limited airflow.
  • Your energy bills could increase because your furnace is turning on more often.
  • Your furnace could break down sooner than it should because a dirty filter causes it to work harder.
  • Your furnace can be cut off from power if an extremely dirty filter causes the breaker to trip.

Depending on what model of furnace you use, your air filter will be inside the blower compartment of your furnace, an attached filter case or wall-mounted return air grille.

Replacing a furnace filter

To replace your filter:

  • Turn off your furnace.
  • Remove the filter and hold it up to the light. If you can’t see light through it, use a new one.
  • Insert 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 replace your filter more often.

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

Examine the Condensate Pan

Otherwise known as drain pans, condensate pans capture water your furnace removes from the air.

If water is seeping 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 isn’t full. If it needs to be drained, use a special pan-cleaning tablet you can purchase at home improvement or hardware stores.
  • If your pan contains a pump, inspect the float switch. If the switch is stuck “up” with liquid in the pan, contact Farnell Mechanical, Inc. at 334-245-4748, because you will probably need a new pump.

Peek Inside Your Furnace

If malfunctions continue, peek inside your furnace’s plastic window to verify 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 other than a steady, colored light or blinking green light, call Farnell Mechanical, Inc. at 334-245-4748. Your furnace may be giving an error code that is calling for professional assistance.

Clean the Flame Sensor

If your furnace tries to start but switches off without blowing heat, a dirty flame sensor could be at fault. When this occurs, your furnace will attempt to ignite three times before a safety feature turns it off 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 HVAC specialists at Farnell Mechanical, Inc. 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:

  • Shut off 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.
  • Take off the furnace’s front panel and follow 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 may go through a sequence of checks before continuing normal operation. If your furnace doesn’t ignite, the sensor may need to be replaced or something else could be wrong. If this happens, get in touch with Farnell Mechanical, Inc. at 334-245-4748 for assistance.

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.

  • Look for 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 starting a fire.
  • Turn the knob to “pilot.”
  • Press 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, get in touch with Farnell Mechanical, Inc. at 334-245-4748.

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.

Farnell Mechanical, Inc. Can Help with Furnace Problems

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

Call us today at 334-245-4748 or use our online scheduler. We’ll come out and figure out the problem.

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