Furnace Repair Checklist
1. Look at the Thermostat
To begin, make certain that your thermostat is telling your heater to turn on.
- Replace the batteries if the screen is blank. If the digital monitor is scrambled, the thermostat may need to be swapped out.
- Ensure the switch is switched to “heat” rather than “off” or “cool.”
- Ensure the program is displaying the correct day and time and is scheduled to “run.” If you’re having problems turning off the program, set the temperature by using the up/down arrows and pressing the “hold” button. This will cause the furnace to ignite if thermostat is causing a problem.
- Increase the temperature setting to 5 degrees above the temperature of the room.
If your heater hasn’t started within several minutes, make sure it has juice by switching the fan switch from “auto” to “on.” If the fan doesn’t start, your furnace may not have power.
If you use a smart thermostat—like one designed by Nest, Ecobee, Lux, Honeywell or Bosch—troubleshooting is very model-specific. Refer to the manufacturer’s website for assistance. If you aren’t able to get your Wi-Fi thermostat to work, contact us at 800-COOLING for heating and cooling service.
2. Examine Breakers and Switches
Next, check if your breaker and furnace switch are on.
- Look for your main electrical panel. If you aren’t sure where it is, look for a metallic metal box in your basement, garage or closet.
- Make certain that your hands and feet aren’t wet before opening the panel or breakers.
- Locate the breaker labeled “furnace” or “heat,” and ensure it’s turned “on.” If the breaker has tripped, it will be in the middle or “off” position.
- With one hand, firmly switch the breaker to the “on” position. If the breaker instantly trips and pops back to “off,” don't try to reset it and contact a team member from Brooks Heating and Air Conditioning at 800-COOLING quickly.
It doesn’t matter how old your furnace is or what brand it is, it has at least one ordinary wall switch installed on or near it.
- Make sure the switch is facing up in the “on” position. If it was switched off, it could take your furnace up to five minutes to turn on. (If you’re unsure 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. Buy a New Air Filter
When we consider furnace breakdowns, a filthy, clogged air filter is frequently the top culprit.
If your filter is too grungy:
- Your furnace won’t keep heating your home, or it might overheat from restricted airflow.
- Your heating costs might increase because your heating system is running more often.
- Your furnace may fail sooner than it should since a dirty filter forces it to overwork.
- Your heating system may be disconnected from power if an excessively dirty filter causes the breaker to trip.
Depending on what make of heating system you have, your air filter can be found within the blower compartment of your heater, an attached filter case or wall-mounted return air grille.
To swap out your filter:
- Switch off your heater.
- Take out the filter and angle it toward the light. If you can’t view light through it, replace it.
- Put in the new filter with the arrow pointing toward the furnace to avoid 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 replace your filter more often.
To make the process go more quickly down the road, use a permanent writing tool on your furnace exterior or ductwork to list the airflow direction and filter size.
4. Check the Condensate Pan
Otherwise known as drain pans, condensate pans catch liquid your heating system removes from the air.
If liquid is seeping from your heating system or its pan has standing water in it, use these steps.
- If your pan includes a drain (look for a PVC pipe), double-check that it isn’t full. If it should be drained, get a special pan-cleaning tablet you can purchase at home improvement or hardware shops.
- If your pan contains a pump, check the float switch. If the switch is stuck “up” with water in the pan, contact us at 800-COOLING, because you will possibly have to get a new pump.
5. Check for Heating Error Codes
If failures keep on happening, take a look within your furnace’s plastic window to check the blower motor’s status. Dependent on the brand, the light might also be attached on the outside of your furnace.
If you notice anything except a solid, colored light or twinkling green light, reach us at 800-COOLING for HVAC service. Your heating system could be emitting an error code that requires professional assistance.
6. Brush off the Flame Sensor
If your furnace attempts to start but shuts off without putting out heated air, a grimy flame sensor could be responsible. When this happens, your heater will attempt to start three times before a safety mechanism powers it down for approximately an hour.
If you feel comfortable with opening up your furnace, gently scrubbing your flame sensor is a task you can do yourself. Or, one of our heating service professionals is able to finish it for you.
If you are fine with cleaning the sensor yourself, you require:
- A 1/4” hex screwdriver or wrench
- Bit of light grit sandpaper, steel wool or emery cloth
- An unused paper towel
As the next step:
- Shut off the furnace’s power with its wall switch or breaker. If your gas valve isn’t electric, you have to shut off the gas in addition.
- Remove the heater’s front panel and track the wire to the flame sensor.
- Unscrew the rod and use your sandpaper, steel wool or emery cloth to gently scrub the metal rod.
- Clear the rod with a paper towel.
- Remount the sensor.
- Secure the furnace doors.
- Turn the furnace’s power back on. It may proceed through a sequence of tests before proceeding with usual heating. If your heater doesn’t turn on, the sensor may have to be replaced or something else could be creating an issue. If this occurs, get in touch with us at 800-COOLING for heating and cooling repair assistance.
7. Reignite the Pilot Light
If you are using an aging heater, the pilot light could be out. To light it, find the instructions on a sheet on your furnace, or use these recommendations.
- Locate the toggle beneath your furnace labeled “pilot,” “on” and “off.”
- Turn the switch to the “off” position.
- Wait at least five minutes to prevent creating a fire.
- Move the dial to “pilot.”
- Press the “reset” button as you move the flame of a long lighter to the pilot light opening.
- Let go of the “reset” switch once the pilot light is ignited.
If you have used the instructions twice and the pilot light still won’t burn or keep ignited, call us at 800-COOLING for furnace service.
Inspect Your Fuel Delivery System
Try turning on a second gas appliance. If it doesn’t work, your natural gas service may be shut off, or you might have run out of propane.