Colorado Springs is Getting Cold, but My Furnace Wont Turn On

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

There are a few fast, low-cost 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 Colorado Springs, Mitchell Heating can assist you. We service most makes of heating systems.

If you need a new heating system, we also do furnace replacement in Colorado Springs.

While you’re chatting with us, think about an annual furnace maintenance plan from Mitchell Heating that might help you avoid problems in the future. We can tell you how frequently your furnace should be examined by one of our NATE-certified experts.

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

Steps for Furnace Troubleshooting

Check the Thermostat

To start, make sure your thermostat is instructing your furnace to start.

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” instead of “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 make the furnace to ignite 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 kicked 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 might not have 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.

  • Look for your house’s main electrical panel. If you aren’t sure 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.
  • Find 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 contact a professional from Mitchell Heating at 719-422-4236 right away.

Regardless of your furnace’s age or brand, it has at least one standard wall switch located on or near 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, 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 often the top culprit.

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 too often.
  • Your furnace could break down prematurely because a dirty filter causes it to overwork.
  • Your furnace can be disconnected from power if an extremely dirty filter causes the breaker to trip.

Depending on what type of furnace you have, 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.
  • Pull out 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 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 more often.

To make the process smoother 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 Mitchell Heating at 719-422-4236, 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 attached on the outside of your furnace.

If you see anything except a steady, colored light or blinking green light, call Mitchell Heating at 719-422-4236. Your furnace may be giving an error code that needs professional service.

Clean the Flame Sensor

If your furnace tries to start but switches off without distributing heat, a dirty flame sensor could be responsible. When this takes place, 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 by yourself. Or, one of our HVAC specialists at Mitchell Heating 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.
  • Lift off the furnace’s front panel and trace the wire to the flame sensor.
  • Unscrew the rod and use your sandpaper, steel wool or emery cloth to carefully 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 proceed through a sequence of checks before continuing regular operation. If your furnace doesn’t start, the sensor may need to be replaced or something else could be wrong. If this happens, get in touch with Mitchell Heating at 719-422-4236 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 Mitchell Heating at 719-422-4236.

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.

Mitchell Heating Can Help with Furnace Problems

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

Call us today at 719-422-4236 or use our online scheduler. We’ll come out and figure out the problem.

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