There are a few quick fixes homeowners can do to prevent a furnace repair call. If your furnace doesn’t turn on, won’t run consistently, or won’t ignite, try the troubleshooting checklist below in advance of getting in touch with an HVAC professional.
If support from a heating and cooling professional is needed, Keystone Heating & AC is available to help the residents of Racine and Kenosha. We can repair most furnace models. While consulting with one of our team members, consider a routine furnace maintenance program that can help alleviate problems down the line. We can provide information about how frequently a heating system ought to be examined by one of our certified technicians.
For a new furnace, Keystone Heating & AC also provides installation services.
Furnace Repair Checklist
1. Look at the Thermostat
To start, make certain the thermostat is telling the furnace to turn on.
- Change the batteries if the screen is empty. If the digital screen is jumbled, the thermostat could need to be replaced.
- Ensure the control is set to “heat” as opposed to “off” or “cool.”
- Make sure the program is showing the appropriate day and time and is programmed to “run.” If there are issues turning off the program, adjust the temperature by utilizing the up/down arrows and holding the “hold” button. This will cause the furnace to ignite if the thermostat is causing trouble.
- Set the temperature to 5 degrees above the room temperature.
If your furnace hasn’t kicked on within a few minutes, make certain that it has power by switching the fan switch from “auto” to “on.” If the fan doesn’t start, the furnace could be without power.
If a smart thermostat is installed (for example, one manufactured by Nest, Ecobee, Lux, Honeywell, or Bosch) troubleshooting is model-specific. Check the manufacturer’s website for support. If the Wi-Fi enabled thermostat is not functioning, contact us at 262-554-1080 for support.
2. Examine Breakers and Switches
Next, check if the breaker and furnace switch are on.
- Locate the main electrical panel (typically a gray metal box in the basement, garage, or a closet).
- Make sure hands and feet aren’t damp or wet before opening the panel or breakers.
- Look for the breaker marked “furnace” or “heat,” and ensure it’s reading “on.” If the breaker has tripped, it will be in the middle or “off” position.
- Steadily turn the breaker to the “on” position. If the breaker immediately trips and pops back to “off,” don't try to reset it and get in touch with Keystone Heating & AC immediately.
- Make sure the lever is facing up in the “on” spot. If it was shut off, it could take the furnace up to five minutes to ignite.
3. Get a New Air Filter
When considering heating issues, a dirty, blocked air filter is regularly the top culprit.
If the furnace filter is excessively dirty:
- Heat won’t keep warming your home, or it may overheat from reduced airflow.
- Heating costs may go up because the furnace is operating more often.
- The furnace could fail sooner than it should because a filthy filter forces it to work harder.
- The furnace might be cut off from power if an excessively filthy filter results in a tripped breaker.
Based on the furnace model, the air filter can be found inside the blower compartment, an attached filter case, or wall-mounted return air grille.
To put in a new filter:
- Switch off the furnace or heater.
- Pull out the filter and tilt it toward the light. If light is not visible, use a new one.
- Insert the new filter with the arrow facing toward the heater to prevent damage.
Flat filters should be replaced once a month, while pleated filters will last about three months. If children or pets are in a home, filter changes may be needed more frequently. To make changing a filter smoother down the road, use a permanent writing tool on the furnace's exterior or ductwork to list the airflow direction and filter size.
4. Examine the Condensate Pan
Commonly known as drain pans, condensate pans capture moisture a furnace system draws from the air. If moisture is leaking from within the heating system or the pan has too much water in it, follow these recommendations:
- If the pan includes a drain (look for a PVC pipe), check that it’s clear. If it needs to be drained, use a special pan-cleaning tablet that an be purchased from a home improvement store or hardware shop.
- If the pan contains a pump, take a look at the float switch. If the switch can’t be moved from the “up” position with liquid in the pan, contact Keystone as a new pump most likely needs to be installed.
5. Look for Heating Error Codes
If failures persist, take a look at the furnace’s plastic window to check the blower motor’s status. Dependent on the brand, the light may also be attached on the outside of the furnace. If anything besides a solid, colored light or twinkling green light is seen, contact us for HVAC service. The furnace may be giving an error code that requires specialized service.
6. Scrub the Flame Sensor
If the furnace tries to run but switches off without blowing heated air, a filthy flame sensor can be at fault. When this occurs, the heater will attempt to turn on three times before a safety feature powers it down for about an hour.
If you are comfortable with taking the panels off of the heater, gently scrubbing the flame sensor may remedy the issue. Or, one of our heating service experts has the ability to perform this task.
Flame sensor cleaning requires:
- A 1/4” hex screwdriver or wrench.
- A bit of light-grit sandpaper, steel wool, or emery cloth.
- A fresh paper towel.
- Disable the furnace’s power by using its wall switch or breaker. If an electric gas valve is not used, the gas must also be turned off.
- Lift off the furnace’s front panel and track the wire to the flame sensor.
- Take off the rod and use sandpaper, steel wool, or emery cloth to gently rub the metal rod.
- Clear the rod with a paper towel.
- Screw the sensor back in.
- Put the furnace doors back on.
- Switch the furnace’s power back on. It might go through a set of inspections before resuming regular operation. If the heating system doesn’t start, the sensor could need to be replaced or something else might be causing a problem. If this occurs, call us at 262-554-1080 for furnace assistance.
7. Light the Pilot Light
It the furnace is an older model, the pilot light could be out. To reignite it, locate the directions on a sheet on your furnace, or use these steps:
- Look for the toggle on the bottom of the heating system marked “pilot,” “on”, and “off.”
- Push the switch to the “off” position.
- Don’t do anything for at least five minutes to avoid creating a fire.
- Turn the knob to “pilot.”
- Push the “reset” lever as a flame from a long lighter is brought to the pilot light opening.
- Release the “reset” switch once the pilot light is ignited.
If the guide was followed twice and the pilot light still won’t light or stay lit, contact us at 262-554-1080 for furnace service.
8. Examine the Fuel Supply
Try using a secondary gas appliance. If it doesn’t work, the natural gas service may be shut off, or the propane supply may be empty.
We Can Assist With Furnace Servicing
Went through the troubleshooting checklist above, but the furnace still doesn’t run?
Call us today at 262-554-1080 or contact us online. We’ll schedule an appointment and pinpoint the trouble.