When your furnace won’t start, doing your own furnace repair in Ames, Iowa, can feel pretty overwhelming.

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 a few speedy, inexpensive fixes you can do on your own 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 contacting an HVAC professional.

If you find you need help from a heating and cooling pro and live in Ames, Haselhoff Air Solutions can assist you. We can repair most makes of heating systems and also provide emergency furnace repair.

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

While you’re talking with us, consider an annual furnace maintenance plan that could help you avoid problems in the future. We can tell you how frequently your furnace should be inspected by one of our NATE-certified Pros.

Follow our easy guide below to get to work on troubleshooting your furnace. Most of these steps don’t require mechanical skills.

Furnace Repair Checklist

1. Check the Thermostat

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

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” rather than “off” or “cool.”

Ensure the program is set to the right day and time and is set to “run.” If you’re having problems overriding the program, set the temperature by using the up/down arrows and press the “hold” button. This will force the furnace to turn on if thermostat programming is causing an issue.

Increase the temperature setting to 5 degrees warmer than the room temperature.

If your furnace hasn’t turned on within several 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 could be without power.

Smart Thermostat

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, call us at 515-450-8739 for heating and cooling service.

2. 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, 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.

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 get in touch with a professional from Haselhoff Air Solutions at 515-450-8739 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, anticipate your furnace could take 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.)

3. Replace the 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 be able to 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 fail prematurely because a dirty filter causes it to overwork.
  • Your furnace can lose power if an extremely dirty filter causes the breaker to trip.

Depending on what model of furnace you own, your air filter can be found inside the blower compartment of your furnace, an attached filter case or wall-mounted return air grille.

To replace your filter:

  1. Turn off your furnace.
  2. Take out the filter and hold it up to the light. If you can’t see light through it, get a new one.
  3. Put in the new filter with the arrow pointing toward the furnace to avoid damage.

Flat filters should be replaced monthly, 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 change your filter more frequently.

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

4. Check for Furnace Error Codes

If malfunctions continue, look 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 other than a steady, colored light or blinking green light, call us at 515-450-8739 for HVAC service. Your furnace may be giving an error code that requires professional help.

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.