Furnace Repair Checklist
1. Check the Thermostat
To start, make certain that your thermostat is signaling your furnace to start.
- Replace the batteries if the monitor is blank. If the digital monitor is jumbled, the thermostat could need to be changed.
- Make sure the button is set to “heat” instead of “off” or “cool.”
- Make sure the program is set to the right day and time and is scheduled to “run.” If you’re having a hard time turning off the setting, set the temperature with the up/down arrows and using the “hold” button. This will cause the furnace to ignite if thermostat is causing a problem.
- Set the temperature setting to 5 degrees hotter than the temperature of the room.
If your furnace hasn’t started within several minutes, make sure 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—such as one made by Nest, Ecobee, Lux, Honeywell or Bosch—troubleshooting is very model-specific. Check the manufacturer’s website for assistance. If you’re still unable to get your Wi-Fi thermostat to work, contact us at 703-260-1148 for heating and cooling service.
2. Check 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 silver metal box in your basement, garage or closet.
- Make sure your hands and feet aren’t wet in advance of using the panel or breakers.
- Locate the breaker labeled “furnace” or “heat,” and double-check it’s turned “on.” If the breaker has tripped, it will be in the middle or “off” position.
- Moving one hand, quickly switch the breaker to the “on” position. If the breaker instantly trips and pops back to “off,” don't try to reset it and call an expert from Air-Right Energy Design, Inc. at 703-260-1148 right away.
It doesn’t matter how old your furnace is or what brand it is, it has at minimum one regular wall switch positioned 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 ignite. (If you’re unaware of where to locate your furnace, take a look at your basement, garage or utility closet. It can also be in a crawl space or attic.)
3. Get a New Air Filter
When we consider heating problems, a grungy, blocked air filter is frequently the top culprit.
If your filter is too dirty:
- Your heater won’t keep heating your home, or it could overheat from restricted airflow.
- Your utility expenses may increase because your heating system is turning on more than it should.
- Your furnace might stop working sooner than it should since a dirty filter forces it to work overtime.
- Your heating system might be disconnected from power if an excessively clogged filter causes the breaker to trip.
Depending on what type of heating system you have, your air filter is located in the interior of the blower compartment of your furnace, an attached filter case or wall-mounted return air grille.
To replace your filter:
- Cut the power to your furnace.
- Take out the filter and tilt it toward the light. If you can’t notice light through it, use a new one.
- Insert the new filter with the arrow facing toward the heater to keep damage from happening.
Flat filters should be replaced once a month, while pleated filters should last about three months. If you have children or pets, you could have to replace your filter more often.
To make the process smoother in the future, draw with a permanent marker on your heater exterior or ductwork to list the airflow direction and filter size.
4. Inspect the Condensate Pan
Otherwise known as drain pans, condensate pans capture water your heating system draws from the air.
If liquid is seeping from within your furnace or its pan has too much water in it, use these guidelines.
- If your pan contains 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 buy at home improvement or hardware stores.
- If your pan contains a pump, take a look at the float switch. If the lever is jammed “up” with standing water in the pan, contact us at 703-260-1148, because you will likely have to install a new pump.
5. Watch for Heater Error Codes
If faults persist, take a look within your heater’s plastic window to confirm the blower motor’s status. Depending on the type, the light might also be attached on the outside of your furnace.
If you note anything except an uninterrupted, colored light or blinking green light, call us at 703-260-1148 for HVAC service. Your heating system could be giving an error code that requires professional help.
6. Clean the Flame Sensor
If your furnace attempts to work but switches off without distributing heat, a dirty flame sensor could be at fault. When this happens, your furnace will try to turn on three times before a safety feature powers it down for approximately an hour.
If you feel confident with taking the panels off your heater, brushing off your flame sensor is something you are able to do on your own. Or, one of our heating service experts can do it for you.
If you want to clean the sensor on your own, you need:
- A 1/4” hex screwdriver or wrench
- Portion of light grit sandpaper, steel wool or emery cloth
- A dry, clean paper towel
- Disable the heater’s power through its wall switch or breaker. If your gas valve isn’t electric, you must turn off the gas along with it.
- Remove 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 carefully clean the metal rod.
- Clean the rod with a paper towel.
- Put the sensor back in.
- Put the furnace doors back on.
- Turn the furnace’s power back on. It could go through a sequence of examinations before proceeding with normal heating. If your furnace doesn’t turn on, the sensor could require replacement or something else could be causing a problem. If this happens, get in touch with us at 703-260-1148 for heating and cooling repair support.
7. Relight the Pilot Light
If you own an outdated furnace, the pilot light could be extinguished. To relight it, locate the guide on a label on your furnace, or use these recommendations.
- Locate the switch beneath your furnace labeled “pilot,” “on” and “off.”
- Turn the switch to the “off” position.
- Don’t do anything for at least five minutes to avoid starting a fire.
- Push the switch to “pilot.”
- Push the “reset” lever as you bring the flame of a long lighter to the pilot light opening.
- Release the “reset” lever once the pilot light is burning.
If you have gone through the guide twice and the pilot light still won’t light or keep ignited, get in touch with us at 703-260-1148 for furnace service.
Examine Your Fuel Supply
Try turning on an additional gas appliance. If it doesn’t operate, your natural gas delivery could be turned off, or you might have run out of propane.