Furnace Repair Checklist
1. Examine the Thermostat
First, make sure your thermostat is instructing your heater to turn on.
- Change the batteries if the screen is blank. If the digital display is jumbled, the thermostat may need to be changed.
- Make sure the button is on “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 setting, adjust the temperature by using the up/down arrows and pressing the “hold” button. This will cause the furnace to ignite if thermostat is causing trouble.
- Increase the temperature setting to 5 degrees above what the room temperature currently is.
If your heating hasn’t started within a couple minutes, make certain that it has power by toggling the fan switch from “auto” to “on.” If the fan doesn’t begin to run, your heater might not have power.
If you have a smart thermostat—like one designed by Nest, Ecobee, Lux, Honeywell or Bosch—troubleshooting will depend on your model. Refer to the manufacturer’s website for support. If you aren’t able to get your Wi-Fi thermostat to work, reach us at 641-316-3360 for heating and cooling service.
2. Inspect Breakers and Switches
Next, verify your breaker and furnace switch are on.
- Look for your main electrical panel. If you have no idea where it is, search for a metallic metal box in your basement, garage or closet.
- Make sure your hands and feet are dry before opening the panel or breakers.
- Find the breaker marked “furnace” or “heat,” and double-check it’s reading “on.” If you discover a tripped breaker, it will be in the middle or “off” spot.
- Using one hand, firmly flip the breaker to the “on” position. If the breaker instantly trips and pops back to “off,” don't try to reset it and call a professional from B & G HVAC at 641-316-3360 quickly.
Regardless of your furnace’s age or brand, it has at least one ordinary wall switch set on or near it.
- Ensure the switch is moved up in the “on” position. If it was turned off, expect your furnace to take up to five minutes to turn on. (If you’re unaware of where to locate your furnace, take a look at your basement, garage or utility closet. It could also be in a crawl space or attic.)
3. Get a New Air Filter
When we think about heater problems, a filthy, full air filter is often to blame.
If your filter is too grungy:
- Your heater won’t keep heating your home, or it might get too warm from limited airflow.
- Your heating expenses might go up because your heater is working too often.
- Your furnace may fail too soon due to the fact a filthy filter causes it to overwork.
- Your heater can be cut off from power if an excessively clogged filter causes the breaker to trip.
Based on what model of heater you own, your air filter will be inside the blower compartment of your heating system, an attached filter case or wall-mounted return air grille.
To put in a new filter:
- Switch off your heater.
- Take out the filter and hold it up to the light. If you can’t see light through it, use a new one.
- Insert the new filter with the arrow pointing toward the heater to prevent damage.
Flat filters need to be replaced once a month, while pleated filters should last about three months. If you have children or pets, you might have to change your filter sooner.
To make the process go more quickly down the line, write with a permanent marker on your furnace exterior or ductwork to indicate the airflow direction and filter size.
4. Check the Condensate Pan
Otherwise known as drain pans, condensate pans hold water your heating system draws from the air.
If water is seeping out of your heating system or its pan has too much water in it, try these steps.
- If your pan includes a drain (look for a PVC pipe), make sure that it isn’t full. If it requires draining, drop in a special pan-cleaning tablet you can purchase at home improvement or hardware stores.
- If your pan contains a pump, check the float switch. If the button is jammed “up” with liquid in the pan, contact us at 641-316-3360, because you will likely have to install a new pump.
5. Watch for Furnace Error Codes
If failures persist, take a look within your furnace’s plastic window to check the blower motor’s status. Subject to the type, the light might also be attached on the exterior of your heating system.
If you note anything except a steady, colored light or flickering green light, reach us at 641-316-3360 for HVAC service. Your heating system might be emitting an error code that requires pro assistance.
6. Clean the Flame Sensor
If your heating system tries to run but turns off without blowing heated air, a grimy flame sensor could be to blame. When this happens, your heating system will try to ignite three times before a safety device turns it off for approximately an hour.
If you feel comfortable with opening up your heater, gently scrubbing your flame sensor is work you are able to do yourself. Or, one of our heating service experts has the ability to do it for you.
If you are fine with cleaning the sensor yourself, you need:
- A 1/4” hex screwdriver or wrench
- Bit of light grit sandpaper, steel wool or emery cloth
- A fresh paper towel
As the next step:
- Turn off the furnace’s power through its wall switch or breaker. If your furnace’s gas valve isn’t electric, you have to turn off the gas as well.
- Lift off the furnace’s front panel and track the wire to the flame sensor.
- Remove the rod and use your sandpaper, steel wool or emery cloth to lightly clean the metal rod.
- Clean the rod with a paper towel.
- Remount the sensor.
- Put the furnace doors back on.
- Turn the furnace’s power back on. It might go through a sequence of checks before proceeding with normal heating. If your heater doesn’t ignite, the sensor might need to be replaced or something else may be causing a problem. If this happens, call us at 641-316-3360 for heating and cooling repair help.
7. Relight the Pilot Light
If you are using an outdated furnace, the pilot light could be out. To reignite it, locate the steps on a sticker on your furnace, or try these steps.
- Locate the lever on the bottom of your furnace labeled “pilot,” “on” and “off.”
- Push the switch to the “off” position.
- Wait at least five minutes to prevent creating a fire.
- Turn the switch to “pilot.”
- Hold down the “reset” switch as you bring the flame of a long lighter to the pilot light opening.
- Release the “reset” button once the pilot light is burning.
If you have used the guide twice and the pilot light still won’t ignite or keep lit, call us at 641-316-3360 for furnace service.
Inspect Your Fuel Source
Try turning on another gas appliance. If it doesn’t operate, your natural gas source may be shut off, or you may have run out of propane.