furnace repair

Port St. Lucie is Getting Cold, but My Furnace Wont Turn On

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

There are a couple of fast, reasonable fixes you can do on your own 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 someone who is experienced and live in Port St. Lucie, Custom Air Systems Inc can provide assistance to you. We work on most brands of heating systems.

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

While you’re chatting with us, think over an annual furnace maintenance plan from Custom Air Systems Inc that might help you avoid problems in the future. We can tell you how frequently your furnace should be inspected by one of our NATE-certified professionals.

Use our easy guide below to start troubleshooting your furnace. Most of these steps don’t require mechanical abilities.

Steps for Furnace Troubleshooting

Check the Thermostat

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

If you have a digital thermostat:

  • Replace 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” rather than “off” or “cool.”
  • Ensure the program is showing the right 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 make the furnace to start if thermostat programming is causing a problem.
  • 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.

  • Look for 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.
  • 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 touch it and call a professional from Custom Air Systems Inc at 772-247-2283 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 close to 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, take a look at 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 problems, a grungy, clogged air filter is regularly to blame.

If your filter is too dirty:

  • Your furnace won’t stay on, or it could overheat from reduced airflow.
  • Your energy bills could be higher because your furnace is turning on more than it should.
  • Your furnace could stop working sooner than it should because a dirty filter causes it to work overtime.
  • 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.
  • Put in 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 get a washable filter that will last about 10 years. If you have children or pets, you may have to put in a new filter more often.

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

Examine the Condensate Pan

Also known as drain pans, condensate pans hold water your furnace draws 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 contains a pump, inspect the float switch. If the switch is stuck “up” with liquid in the pan, contact Custom Air Systems Inc at 772-247-2283, because you will probably need a new pump.

Peek Inside Your Furnace

If malfunctions keep on happening, peek inside your furnace’s plastic window to confirm 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 Custom Air Systems Inc at 772-247-2283. Your furnace may be emitting an error code that needs professional service.

Clean the Flame Sensor

If your furnace tries to start but shuts off without putting out heat, a dirty flame sensor could be at fault. When this takes place, your furnace will make an attempt to ignite 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 on your own. Or, one of our HVAC experts at Custom Air Systems 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.
  • 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 set of checks before proceeding with usual operation. If your furnace doesn’t turn on, the sensor may need to be replaced or something else might be wrong. If this happens, call Custom Air Systems Inc at 772-247-2283 for assistance.

Relight the Pilot Light

If you own 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.”
  • Push 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 Custom Air Systems Inc at 772-247-2283.

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.

Custom Air Systems Inc Can Help with Furnace Problems

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

Call us today at 772-247-2283 or use our online scheduler. We’ll come out and pinpoint the problem.

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