Furnace Repair Checklist
1. Examine the Thermostat
To begin, make sure your thermostat is signaling your heat to start.
- Replace the batteries if the screen is not displaying anything. If the digital monitor is messed up, the thermostat may need to be swapped out.
- Ensure the control is set to “heat” instead of “off” or “cool.”
- Make certain the program is showing the right day and time and is scheduled to “run.” If you’re having trouble turning off the schedule, set the temperature by using the up/down arrows and holding the “hold” button. This will cause the furnace to start if thermostat is causing trouble.
- Increase the temperature setting to 5 degrees above the room temperature.
If your heating hasn’t kicked on within a few minutes, ensure it has juice by moving the fan switch from “auto” to “on.” If the fan doesn’t start, your heater could be without power.
If you utilize a smart thermostat—like one manufactured by Nest, Ecobee, Lux, Honeywell or Bosch—troubleshooting will be determined by the model you have. Refer to the manufacturer’s website for help. If you still can’t get your Wi-Fi thermostat to operate, reach us at 734-284-1224 for heating and cooling service.
2. Examine Breakers and Switches
Next, verify your breaker and furnace switch are on.
- Find your main electrical panel. If you have no idea where it is, keep an eye out for a gray metal box in your basement, garage or closet.
- Ensure your hands and feet are dry prior to opening the panel or breakers.
- Find the breaker titled “furnace” or “heat,” and make sure it’s moved to “on.” If you find that the breaker tripped, it will be in the middle or “off” area.
- Using one hand, quickly flip the breaker to the “on” position. If the breaker immediately trips and pops back to “off,” don't try to reset it and contact an expert from Gee & Missler Heating & Air Conditioning at 734-284-1224 right away.
No matter your furnace’s age or brand, it has at least one ordinary wall switch located on or close to it.
- Make sure the control is facing up in the “on” placement. If it was turned off, expect your furnace to take up to five minutes to start. (If you don’t know where to locate your furnace, check your basement, garage or utility closet. It can also be in a crawl space or attic.)
3. Get a New Air Filter
When we think about furnace problems, a dirty, full air filter is often the top offender.
If your filter is too grungy:
- Your furnace won’t stay on, or it may overheat from limited airflow.
- Your energy costs might be higher because your heating system is operating more often.
- Your heater could fail prematurely due to the fact a dirty filter causes it to work overtime.
- Your heating system may be cut off from power if an excessively filthy filter is the cause of a tripped breaker.
While it depends on what make of furnace you use, your air filter will be in the interior of the blower compartment of your furnace, an attached filter case or wall-mounted return air grille.
To put in a new filter:
- Switch off your heating system.
- Pull out the filter and hold it up to the light. If you can’t notice light through it, get a new one.
- Put in the new filter with the arrow facing toward the furnace to keep damage from happening.
Flat filters need to be replaced every month, while pleated filters should last about three months. If you have children or pets, you might have to change your filter more frequently.
To make the procedure smoother down the road, write with a permanent writing tool on your heating system exterior or ductwork to indicate the airflow direction and filter size.
4. Check the Condensate Pan
Also known as drain pans, condensate pans capture moisture your heating system draws from the air.
If moisture is dripping from your heater or its pan has too much water in it, follow these steps.
- If your pan includes a drain (look for a PVC pipe), make sure that it isn’t clogged. If it requires draining, get a special pan-cleaning tablet you can buy at home improvement or hardware retailers.
- If your pan uses a pump, check the float switch. If the lever is stuck “up” with water in the pan, reach us at 734-284-1224, because you will probably have to get a new pump.
5. Check for Heater Error Codes
If failures keep on happening, look inside your heating system’s plastic window to verify the blower motor’s status. Dependent on the type, the light may also be fixed on the surface of your furnace.
If you notice anything else besides an uninterrupted, colored light or twinkling green light, call us at 734-284-1224 for HVAC service. Your heating system could be communicating an error code that requires specialized help.
6. Scrub the Flame Sensor
If your furnace makes an effort to run but switches off without blowing heat, a dusty flame sensor might be to blame. When this happens, your heater will attempt to turn on three times before a safety feature turns it off for approximately an hour.
If you feel confident with removing the panels from your furnace, cleaning your flame sensor is a job you are able to do on your own. Or, one of our heating service professionals has the ability to finish it for you.
If you are fine with cleaning the sensor yourself, you should have:
- A 1/4” hex screwdriver or wrench
- Piece of light grit sandpaper, steel wool or emery cloth
- A dry, clean paper towel
- Disable the heater’s power by using its wall switch or breaker. If your furnace’s gas valve isn’t electric, you must turn off the gas along with it.
- Remove the heating system’s front panel and trace the wire to the flame sensor.
- Take off the rod and use your sandpaper, steel wool or emery cloth to gently rub the metal rod.
- Clear the rod with a paper towel.
- Put the sensor back in.
- Replace the furnace doors.
- Turn the furnace’s power back on. It could run through a series of inspections before continuing normal running. If your heater doesn’t start, the sensor could need to be replaced or something else might be causing a problem. If this occurs, contact us at 734-284-1224 for heating and cooling repair help.
7. Light the Pilot Light
If you are using an older heater, the pilot light could be extinguished. To relight it, look for the steps on a sheet on your furnace, or use these recommendations.
- Locate the toggle beneath your furnace labeled “pilot,” “on” and “off.”
- Push the switch to the “off” position.
- Don’t do anything for at least five minutes to avoid starting a fire.
- Turn the switch to “pilot.”
- Press the “reset” switch as you bring the flame of a long lighter to the pilot light opening.
- Let go of the “reset” button once the pilot light is burning.
If you have followed the instructions twice and the pilot light still won’t burn or remain lit, contact us at 734-284-1224 for furnace service.
Check Your Gas Supply
Try switching on an additional gas appliance. If it doesn’t function, your natural gas delivery might be turned off, or you could be out of propane.