When your furnace won’t start, doing your own furnace repair in Monroe, Wisconsin, can feel pretty overwhelming.
Fixing your furnace might feel like an intimidating undertaking when your heat won’t start. But it doesn’t have to be like that.
There are several quick, low-cost fixes you can do yourself 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 contacting an HVAC professional.
If you find you need help from a heating and cooling professional and live in Monroe, Lanz Furnace and Fireplace can assist you. We can repair most types of heating systems and also provide emergency furnace repair.
If you’re ready for a new heating system, we also provide furnace installation.
While you’re in touch with us, think over a regular furnace maintenance plan that might help you avoid repairs in the future. We can tell you how regularly your furnace should be examined by one of our certified professionals.
Go through our easy guide below to get to work on troubleshooting your furnace. Most of these steps don’t require mechanical expertise.
Furnace Repair Checklist
1. Check the Thermostat
To start, make sure your thermostat is instructing your furnace to ignite.
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” rather than “off” or “cool.”
Ensure the program is set to the appropriate 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 cause the furnace to start if thermostat programming is causing trouble.
Increase the temperature setting to 5 degrees warmer than the room temperature.
If your furnace hasn’t kicked on within a couple 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 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 608-291-3606 for heating and cooling service.
2. 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 don’t know where it is, look 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.
Locate 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 Lanz Furnace and Fireplace at 608-291-3606 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.)
3. Replace the Air Filter
When it comes to furnace issues, a grungy, clogged air filter is regularly to blame.
If your filter is too dirty:
- Your furnace won’t stay on, or it could overheat from reduced airflow.
- Your energy bills could increase because your furnace is turning on more often.
- Your furnace could break down too soon because a dirty filter causes it to work overtime.
- Your furnace can be cut off from power if an excessively dirty filter causes the breaker to trip.
Depending on what make 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, replace it.
- Insert the new filter with the arrow pointing toward the furnace to avoid damage.
Flat filters should be replaced once a month, while pleated filters should last about three months. You can also buy a washable filter that will last about 10 years. If you have children or pets, you may have to change your filter more often.
To make the process go more quickly 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
Commonly known as drain pans, condensate pans catch water your furnace pulls 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 full. If it needs to be drained, use a special pan-cleaning tablet you can purchase at home improvement or hardware stores.
- If your pan contains a pump, take a look at the float switch. If the switch is stuck “up” with liquid in the pan, contact us at 608-291-3606, because you will likely need a new pump.
5. 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 fixed on the outside of your furnace.
If you see anything except a steady, colored light or blinking green light, call us at 608-291-3606 for HVAC service. Your furnace may be giving an error code that requires professional assistance.
6. Clean the Flame Sensor
If your furnace tries to start but shuts off without distributing heat, a dirty flame sensor could be responsible. When this happens, your furnace will make an attempt to start 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 yourself. Or, one of our heating service professionals 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:
- Disable 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.
- Remove 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 could run through a set of checks before continuing normal operation. If your furnace doesn’t ignite, the sensor may need to be replaced or something else may be wrong. If this happens, get in touch with us at 608-291-3606 for heating and cooling repair assistance.
7. Relight the Pilot Light
If you have 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.
- 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 creating 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 us at 608-291-3606 for furnace service.
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.
We Can Help with HVAC Repair
Followed our troubleshooting guide but your furnace still won’t work?
Call us today at 608-291-3606 or contact us online. We’ll come out and figure out the problem.