furnace repair

Rock Hill is Getting Cold, but My Furnace Wont Turn On

Troubleshooting your furnace might feel like an intimidating job when your heat won’t work. But it doesn’t have to be like that.

There are several fast, low-cost fixes you can do 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 Rock Hill, US Air Heating and Cooling can assist you. We service most brands of heating systems.

If you’re ready for a new heating system, we also provide furnace replacement in Rock Hill.

While you’re talking with us, think about a regular furnace maintenance plan from US Air Heating and Cooling that might help you avoid problems in the future. We can tell you how often your furnace should be inspected by one of our NATE-certified professionals.

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

Steps for Furnace Troubleshooting

Check the Thermostat

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

If you have a digital thermostat:

  • Swap out 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 right day and time and is set to “run.” If you’re having trouble overriding the program, set the temperature by using the up/down arrows and press the “hold” button. This will make 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 a couple minutes, make sure it has power by toggling the fan switch from “auto” to “on.” If the fan doesn’t run, your furnace could be without power.

If you have a smart thermostat—like one made by Nest, Ecobee, Lux, Honeywell or Bosch—troubleshooting is very model-specific. Take a look at 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 aren’t sure 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 US Air Heating and Cooling at 803-220-0761 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 turn on. (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 issues, a filthy, clogged air filter is frequently to blame.

If your filter is too dirty:

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

Depending on what type of furnace you use, your air filter can be found 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 angle it toward the light. If you can’t see light through it, replace it.
  • Install the new filter with the arrow pointing toward the furnace to avoid damage.

Flat filters should be replaced every month, while pleated filters should last about three months. You can also buy a washable filter that will last about 10 years. If you have children or pets, you may have to put in a new filter sooner.

To make the process smoother 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

Also known as drain pans, condensate pans capture 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 isn’t clogged. If it needs to be drained, use a special pan-cleaning tablet you can buy at home improvement or hardware stores.
  • If your pan uses a pump, inspect the float switch. If the switch is stuck “up” with water in the pan, contact US Air Heating and Cooling at 803-220-0761, because you will likely need a new pump.

Peek Inside Your Furnace

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

If you see anything other than a steady, colored light or blinking green light, call US Air Heating and Cooling at 803-220-0761. Your furnace may be communicating an error code that requires professional service.

Clean the Flame Sensor

If your furnace tries to start but shuts off without blowing heat, a dirty flame sensor could be at fault. When this happens, your furnace will attempt to start 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 US Air Heating and Cooling 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 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 may proceed through a set of checks before proceeding with normal operation. If your furnace doesn’t start, the sensor may need to be replaced or something else may be wrong. If this happens, contact US Air Heating and Cooling at 803-220-0761 for assistance.

Relight the Pilot Light

If you are using an older furnace, the pilot light could be extinguished. 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 creating 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 US Air Heating and Cooling at 803-220-0761.

Check Your Fuel Source

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

US Air Heating and Cooling Can Help with Furnace Problems

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

Call us today at 803-220-0761 or use our online scheduler. We’ll come out and diagnose the problem.

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