furnace repair

Grimes is Getting Cold, but My Furnace Wont Turn On

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

There are several fast, reasonable fixes you can do on your own 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 calling an HVAC professional.

If you find you need help from an expert and live in Grimes, Heartland Heating & Cooling can assist you. We repair most types of heating systems.

If you’re ready for a new heating system, we also do furnace replacement in Grimes.

While you’re talking with us, consider a regular furnace maintenance plan from Heartland Heating & Cooling that might help you avoid breakdowns in the future. We can tell you how frequently your furnace should be checked by one of our NATE-certified professionals.

Use 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

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

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” instead of “off” or “cool.”
  • Ensure the program is showing the appropriate 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 turn on 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 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.

  • Locate your house’s main electrical panel. If you don’t know 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,” leave it alone and call a professional from Heartland Heating & Cooling at 515-344-3579 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, check 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 regularly the top culprit.

If your filter is too dirty:

  • Your furnace won’t stay on, or it could overheat from restricted airflow.
  • Your energy bills could go up because your furnace is turning on too often.
  • Your furnace could fail sooner than it should because a dirty filter causes it to overwork.
  • Your furnace can be cut off from power if an excessively dirty filter causes the breaker to trip.

Depending on what type of furnace you use, 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.
  • Remove the filter and tilt it toward the light. If you can’t see light through it, get 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 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

Also known as drain pans, condensate pans hold water your furnace removes from the air.

If water is leaking 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’s clear. If it needs to be drained, use a special pan-cleaning tablet you can get at home improvement or hardware stores.
  • If your pan uses a pump, check the float switch. If the switch is stuck “up” with water in the pan, contact Heartland Heating & Cooling at 515-344-3579, because you will likely 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 mounted on the outside of your furnace.

If you see anything other than a steady, colored light or blinking green light, call Heartland Heating & Cooling at 515-344-3579. Your furnace may be giving an error code that requires professional help.

Clean the Flame Sensor

If your furnace tries to start but turns off without putting out heat, a dirty flame sensor could be to blame. When this takes place, your furnace will make an attempt to turn on 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 on your own. Or, one of our HVAC specialists at Heartland Heating & 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:

  • 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.
  • Lift 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 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 could proceed through a set of checks before resuming regular operation. If your furnace doesn’t ignite, the sensor may need to be replaced or something else might be wrong. If this happens, call Heartland Heating & Cooling at 515-344-3579 for assistance.

Relight the Pilot Light

If you have 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.

  • Find 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, call Heartland Heating & Cooling at 515-344-3579.

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.

Heartland Heating & Cooling Can Help with Furnace Problems

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

Call us today at 515-344-3579 or use our online scheduler. We’ll come out and diagnose the problem.

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