Furnace Repair Checklist
1. Look at the Thermostat
To begin, make sure your thermostat is signaling your furnace to turn on.
Digital Thermostat
- Replace the batteries if the screen is blank. If the digital screen is mixed up, the thermostat might need to be changed.
- Ensure the switch is on “heat” rather than “off” or “cool.”
- Make certain the program is displaying the correct day and time and is scheduled to “run.” If you’re having problems overriding the program, regulate 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.
- Set the temperature setting to 5 degrees warmer than the temperature of the room.
If your heat hasn’t kicked on within a couple minutes, make sure it has power by changing the fan switch from “auto” to “on.” If the fan doesn’t operate, your furnace may not have power.
Smart Thermostat
If you use a smart thermostat—such as one manufactured by Nest, Ecobee, Lux, Honeywell or Bosch—troubleshooting will depend on your model. Refer to the manufacturer’s website for assistance. If you aren’t able to get your Wi-Fi thermostat to work, call us at 520-357-4912 for heating and cooling service.
2. Inspect Breakers and Switches
Next, verify your breaker and furnace switch are on.
- Find your main electrical panel. If you don’t know where it is, search for a gray metal box in your basement, garage or closet.
- Make certain that your hands and feet aren’t moist in advance of using the panel or breakers.
- Locate the breaker marked “furnace” or “heat,” and ensure it’s turned “on.” If the breaker has tripped, it will be in the middle or “off” area.
- With one hand, quickly turn the breaker to the “on” position. If the breaker immediately trips and pops back to “off,” don't try to reset it and get in touch with an expert from Ambient Air at 520-357-4912 right away.
It doesn’t matter how old your furnace is or what brand it is, it has at minimum one ordinary wall switch placed on or near it.
- Make certain the control is moved up in the “on” position. If it was switched off, it could take your furnace up to five minutes to ignite. (If you’re unaware of where your furnace is located, check your basement, garage or utility closet. It might also be in a crawl space or attic.)
3. Replace the Air Filter
When we consider furnace issues, a filthy, full air filter is often to blame.
If your filter is too dirty:
- Your heating system won’t stay on, or it may overheat from restricted airflow.
- Your gas costs could be higher because your heat is running too often.
- Your heating system might fail prematurely due to the fact a dirty filter forces it to work overtime.
- Your heating system may be disconnected from power if an excessively clogged filter is the cause of a tripped breaker.
Depending on what type of heater you use, your air filter is located in the interior of the blower compartment of your heating system, an attached filter case or wall-mounted return air grille.
To swap out your filter:
- Turn off your furnace.
- Take out the filter and tilt it toward the light. If you can’t view light through it, get a new one.
- Insert the new filter with the arrow pointing toward the heating system to avoid damage.
Flat filters ought 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 procedure go more quickly down the road, draw with a permanent pen on your furnace housing or ductwork to list the airflow direction and filter size.
4. Check the Condensate Pan
Also known as drain pans, condensate pans hold liquid your furnace pulls from the air.
If moisture is dripping out of your heater or its pan is overflowing, try these guidelines.
- If your pan has a drain (look for a PVC pipe), make sure that it isn’t clogged. If it requires draining, use a special pan-cleaning tablet you can get at home improvement or hardware retailers.
- If your pan contains a pump, inspect the float switch. If the switch can’t be moved from the “up” position with liquid in the pan, call us at 520-357-4912, because you will likely have to install a new pump.
5. Watch for Heater Error Codes
If faults keep on happening, take a look inside your furnace’s plastic window to check the blower motor’s status. Subject to the model, the light may also be attached on the outside of your furnace.
If you see anything else besides a steady, colored light or flickering green light, call us at 520-357-4912 for HVAC service. Your heating system may be emitting an error code that requires pro assistance.
6. Clean the Flame Sensor
If your furnace tries to start but switches off without putting out heat, a dirty flame sensor could be at fault. When this occurs, your furnace will attempt to start three times before a safety feature turns it off for approximately an hour.
If you feel okay with opening up your heater, cleaning your flame sensor is something you can do yourself. Or, one of our heating service specialists can complete it for you.
If you are confident cleaning the sensor yourself, you should have:
- A 1/4” hex screwdriver or wrench
- Section of light grit sandpaper, steel wool or emery cloth
- A fresh paper towel
As the next step:
- Turn off the furnace’s power with its wall switch or breaker. If you don’t have an electric gas valve, you must switch off the gas along with it.
- Take off the heater’s front panel and trace the wire to the flame sensor.
- Unscrew the rod and use your sandpaper, steel wool or emery cloth to gently clean 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 might run through a sequence of inspections before continuing regular heating. If your heating system doesn’t turn on, the sensor might have to be replaced or something else could be causing a problem. If this takes place, get in touch with us at 520-357-4912 for heating and cooling repair help.
7. Relight the Pilot Light
If you have an older heating system, the pilot light could be extinguished. To relight it, locate the guide on a sticker on your heater, or try these recommendations.
- Look for the lever below your furnace labeled “pilot,” “on” and “off.”
- Push the switch to the “off” position.
- Don’t do anything for at least five minutes to prevent starting a fire.
- Push the switch to “pilot.”
- Push the “reset” lever as you push the flame of a long lighter to the pilot light opening.
- Depress the “reset” switch once the pilot light is lit.
If you have used the instructions twice and the pilot light still won’t light or stay burning, get in touch with us at 520-357-4912 for furnace service.
Check Your Energy Source
Try using an additional gas appliance. If it doesn’t work, your natural gas source could be turned off, or you could be out of propane.