When your furnace won’t start, doing your own furnace repair in Rapid City, South Dakota, can feel pretty overwhelming.
Troubleshooting your furnace might feel like a challenging job when your heat won’t work. But it doesn’t have to be like that.
There are a couple of time-saving, 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 a heating and cooling pro and live in Rapid City, Precision Mechanical can help you. We can repair most brands of heating systems and also provide emergency furnace repair.
If you need a new heating system, we also provide furnace installation.
While you’re talking with us, think over a routine furnace maintenance plan that might help you avoid breakdowns in the future. We can tell you how frequently your furnace should be inspected by one of our NATE-certified professionals.
Go through our easy guide below to start troubleshooting your furnace. Most of these steps don’t require mechanical expertise.
Furnace Repair Checklist
1. Check the Thermostat
To begin, 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” instead of “off” or “cool.”
Ensure the program is set to 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 force the furnace to start 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 few minutes, make sure it has power by toggling the fan switch from “auto” to “on.” If the fan doesn’t run, your furnace might not have 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 605-206-3766 for heating and cooling service.
2. 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 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,” leave it alone and call a professional from Precision Mechanical at 605-206-3766 right away.
Regardless of your furnace’s age or brand, 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 start. (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 breakdown, a dirty, clogged air filter is often the top offender.
If your filter is too dirty:
- Your furnace won’t keep heating your home, or it could overheat from limited airflow.
- Your energy bills could go up because your furnace is turning on more often.
- Your furnace could break down sooner than it should because a dirty filter causes it to work harder.
- Your furnace can lose power if an extremely dirty filter causes the breaker to trip.
Depending on what type 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.
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.
- Add 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 get a washable filter that will last about 10 years. If you have children or pets, you may have to replace your filter sooner.
To make the process smoother in the future, use a permanent marker on your furnace housing or ductwork to indicate the airflow direction and filter size.
4. Inspect the Condensate Pan
Otherwise known as drain pans, condensate pans hold water your furnace removes from the air.
If water is dripping 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 clogged. If it needs to be drained, use a special pan-cleaning tablet you can buy at home improvement or hardware stores.
- If your pan has a pump, check the float switch. If the switch is stuck “up” with water in the pan, contact us at 605-206-3766, because you will probably need a new pump.
5. Check for Furnace Error Codes
If malfunctions keep on happening, take a look inside your furnace’s plastic window to check 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 us at 605-206-3766 for HVAC service. Your furnace may be giving an error code that needs professional service.
6. Clean the Flame Sensor
If your furnace tries to start but turns off without putting out heat, a dirty flame sensor could be at fault. When this happens, your furnace will 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 heating service experts 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 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 proceed through a set of checks before proceeding with normal operation. If your furnace doesn’t ignite, the sensor may need to be replaced or something else could be wrong. If this happens, get in touch with us at 605-206-3766 for heating and cooling repair assistance.
7. 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.
- Look for 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 sparking 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 us at 605-206-3766 for furnace service.
Check Your Fuel Source
Try using another gas appliance. If it doesn’t work, your natural gas service could be turned off, or you could be out of propane.
We Can Help with HVAC Repair
Followed our troubleshooting guide but your furnace still won’t work?
Call us today at 605-206-3766 or contact us online. We’ll come out and figure out the problem.