Furnace Repair Checklist
1. Check the Thermostat
To start, ensure your thermostat is telling your heat to start.
Digital Thermostat
- Swap out the batteries if the monitor is not displaying anything. If the digital screen is messed up, the thermostat may need to be swapped out.
- Ensure the control is on “heat” rather than “off” or “cool.”
- Ensure the program is displaying the appropriate day and time and is programmed to “run.” If you’re having trouble overriding the setting, regulate the temperature by utilizing the up/down arrows and holding the “hold” button. This will cause the furnace to ignite if thermostat is causing a problem.
- Turn the temperature setting to 5 degrees warmer than what the room temperature currently is.
If your heating hasn’t started within a few minutes, make sure it has power by switching the fan switch from “auto” to “on.” If the fan doesn’t operate, your heating system may not have power.
Smart Thermostat
If you have a smart thermostat—like one manufactured by Nest, Ecobee, Lux, Honeywell or Bosch—troubleshooting is very model-specific. Take a look at the manufacturer’s website for help. If you’re still unable to get your Wi-Fi thermostat to work, call us at 301-960-3247 for heating and cooling service.
2. Check Breakers and Switches
Next, check if your breaker and furnace switch are on.
- Find your main electrical panel. If you don’t know where it is, keep an eye out for a metallic metal box in your basement, garage or closet.
- Ensure your hands and feet aren’t moist in advance of touching the panel or breakers.
- Find the breaker labeled “furnace” or “heat,” and double-check it’s switched “on.” If you find that the breaker tripped, it will be in the middle or “off” area.
- Moving one hand, steadily flip the breaker to the “on” position. If the breaker trips right away and pops back to “off,” don't try to reset it and call a professional from H&C Heating and Cooling at 301-960-3247 quickly.
No matter your furnace’s age or brand, it has at minimum one ordinary wall switch positioned on or near it.
- Make sure the switch is facing up in the “on” placement. If it was turned off, it could take your furnace up to five minutes to start. (If you’re unaware of where to find your furnace, look in your basement, garage or utility closet. It might also be in a crawl space or attic.)
3. Replace the Air Filter
When it comes to heating issues, a grungy, clogged air filter is regularly to blame.
If your filter is too grungy:
- Your heater won’t stay on, or it might get too warm from reduced airflow.
- Your utility bills might increase because your heat is working more than it should.
- Your heater may fail sooner than it should since a dirty filter triggers it to overwork.
- Your heating system can be disconnected from power if an excessively filthy filter causes the breaker to trip.
Depending on what model of heater you use, your air filter is located inside the blower compartment of your heater, an attached filter case or wall-mounted return air grille.
To replace your filter:
- Turn off your furnace.
- Pull out the filter and tilt it toward the light. If you can’t notice light through it, use a new one.
- Install the new filter with the arrow pointing toward the furnace to prevent damage.
Flat filters need to be replaced monthly, while pleated filters should last about three months. If you have children or pets, you may have to put in a new filter sooner.
To make the process smoother in the future, write with a permanent marker on your furnace exterior or ductwork to show the airflow direction and filter size.
4. Examine the Condensate Pan
Also known as drain pans, condensate pans capture moisture your heating system pulls from the air.
If liquid is dripping from within your heater or its pan is overflowing, try these steps.
- If your pan contains a drain (look for a PVC pipe), check that it isn’t clogged. If it should be drained, get a special pan-cleaning tablet you can purchase at home improvement or hardware shops.
- If your pan has a pump, take a look at the float switch. If the lever can’t be moved from the “up” position with water in the pan, reach us at 301-960-3247, because you will likely have to install a new pump.
5. Watch for Heating Error Codes
If faults keep on happening, peek at your heating system’s plastic window to verify the blower motor’s status. Dependent on the brand, the light could also be fixed on the exterior of your heating system.
If you notice anything other than a steady, colored light or twinkling green light, reach us at 301-960-3247 for HVAC service. Your heating system might be communicating an error code that needs pro help.
6. Brush off the Flame Sensor
If your heater attempts to run but turns off without putting out warm air, a dusty flame sensor might be responsible. When this occurs, your heater will attempt to start three times before a safety device shuts it down for about an hour.
If you feel comfortable with opening up your heating system, cleaning your flame sensor is a job you are able to do yourself. Or, one of our heating service experts can complete it for you.
If you are confident cleaning the sensor yourself, you need:
- A 1/4” hex screwdriver or wrench
- Portion of light grit sandpaper, steel wool or emery cloth
- An unused paper towel
Then:
- Shut off the heater’s power with its wall switch or breaker. If your gas valve isn’t electric, you will need to shut off the gas as well.
- Lift off the furnace’s front panel and track the wire to the flame sensor.
- Take off the rod and use your sandpaper, steel wool or emery cloth to carefully clean the metal rod.
- Wipe off the rod with a paper towel.
- Screw the sensor back in.
- Replace the furnace doors.
- Restore power to the furnace. It could run through a series of tests before resuming normal running. If your heating system doesn’t ignite, the sensor may need to be replaced or something else may be causing a problem. If this happens, get in touch with us at 301-960-3247 for heating and cooling repair help.
7. Light the Pilot Light
If you have an aging heater, the pilot light could be extinguished. To reignite it, find the directions on a sheet on your heater, or use these steps.
- Find the lever beneath your heater that says “pilot,” “on” and “off.”
- Turn the switch to the “off” position.
- Take a break for at least five minutes to limit the possibility for creating a fire.
- Push the dial to “pilot.”
- Hold down 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 lit.
If you have gone through the list twice and the pilot light still won’t ignite or stay lit, get in touch with us at 301-960-3247 for furnace service.
Examine Your Energy Source
Try switching on another gas appliance. If it doesn’t work, your natural gas service may be turned off, or you may have run out of propane.