furnace repair

Huntsville is Getting Cold, but My Furnace Wont Turn On

Figuring out a furnace-related problem might feel like a daunting task when your heat won’t work. But it doesn’t have to be like that.

There are a couple of time-saving, inexpensive fixes you can do by yourself to prevent 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 an expert and live in Huntsville, All Weather Heating & Air Conditioning Inc can help you. We service most makes of heating systems.

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

While you’re talking with us, consider a routine furnace maintenance plan from All Weather Heating & Air Conditioning Inc that might help you avoid repairs in the future. We can tell you how frequently your furnace should be examined by one of our NATE-certified professionals.

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

Steps for Furnace Troubleshooting

Check the Thermostat

To begin, make sure your thermostat is signaling your furnace to start.

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 appropriate 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 cause the furnace to ignite if thermostat programming is causing trouble.
  • Increase the temperature setting to 5 degrees warmer than the room temperature.
Digital Thermostat

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 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.

  • Find your house’s main electrical panel. If you have no idea where it is, look 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.
  • Locate 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 call a professional from All Weather Heating & Air Conditioning Inc at 256-801-4701 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, anticipate your furnace could 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 issues, a grungy, clogged air filter is frequently the top culprit.

If your filter is too dirty:

  • Your furnace won’t keep heating your home, or it could overheat from restricted airflow.
  • Your energy bills could be higher because your furnace is turning on too often.
  • Your furnace could fail sooner than it should because a dirty filter causes it to work overtime.
  • Your furnace can be cut off from power if an overly dirty filter causes the breaker to trip.

Depending on what make of furnace you own, your air filter is located 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.
  • Pull out the filter and angle it toward the light. If you can’t see light through it, use a new one.
  • Install 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 put in a new filter sooner.

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

Also known as drain pans, condensate pans hold 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 buy at home improvement or hardware stores.
  • If your pan uses a pump, inspect the float switch. If the switch is stuck “up” with liquid in the pan, contact All Weather Heating & Air Conditioning Inc at 256-801-4701, because you will probably need a new pump.

Peek Inside Your Furnace

If malfunctions keep on happening, take a look inside your furnace’s plastic window to confirm 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 else besides a steady, colored light or blinking green light, call All Weather Heating & Air Conditioning Inc at 256-801-4701. Your furnace may be giving an error code that requires professional assistance.

Clean the Flame Sensor

If your furnace tries to start but turns off without blowing 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 shuts 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 HVAC specialists at All Weather Heating & Air Conditioning 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:

  • Turn 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 lightly 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 continuing usual operation. If your furnace doesn’t turn on, the sensor may need to be replaced or something else may be wrong. If this happens, call All Weather Heating & Air Conditioning Inc at 256-801-4701 for assistance.

Relight the Pilot Light

If you are using an older furnace, the pilot light could be out. 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.”
  • 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, contact All Weather Heating & Air Conditioning Inc at 256-801-4701.

Check Your Fuel Source

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

All Weather Heating & Air Conditioning Inc Can Help with Furnace Problems

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

Call us today at 256-801-4701 or use our online scheduler. We’ll come out and pinpoint the problem.

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