Furnace Repair Checklist
1. Look at the Thermostat
To start, ensure your thermostat is telling your furnace to turn on.
- Swap out the batteries if the screen is empty. If the digital display is scrambled, the thermostat could need to be swapped out.
- Ensure the control is set to “heat” instead of “off” or “cool.”
- Ensure the program is showing the appropriate day and time and is programmed to “run.” If you’re having a hard time getting out of the schedule, adjust the temperature by using the up/down arrows and holding the “hold” button. This will cause the furnace to turn on if thermostat is causing a problem.
- Set the temperature setting to 5 degrees hotter than what the room temperature currently is.
If your heat hasn’t kicked on within a few minutes, make certain that it has power by changing the fan switch from “auto” to “on.” If the fan doesn’t begin to run, your heater could be without power.
If you have a smart thermostat—like one made by Nest, Ecobee, Lux, Honeywell or Bosch—troubleshooting is very model-specific. Check the manufacturer’s website for assistance. If you aren’t able to get your Wi-Fi thermostat to operate, call us at 928-251-4327 for heating and cooling service.
2. Examine Breakers and Switches
Next, confirm your breaker and furnace switch are on.
- Look for 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 wet in advance of touching the panel or breakers.
- Look for the breaker marked “furnace” or “heat,” and double-check it’s moved to “on.” If you discover a tripped breaker, it will be in the middle or “off” spot.
- Using one hand, firmly switch the breaker to the “on” position. If the breaker immediately trips and pops back to “off,” don't try to reset it and call a team member from Connolly Electric & Mechanical at 928-251-4327 quickly.
No matter your furnace’s age or brand, it has at minimum one regular wall switch set on or close to it.
- Make sure the switch is flipped up in the “on” spot. If it was switched off, expect your furnace to take up to five minutes to turn on. (If you don’t know where to find your furnace, look in your basement, garage or utility closet. It can also be in a crawl space or attic.)
3. Replace the Air Filter
When we consider heating problems, a grungy, clogged air filter is regularly the top culprit.
If your filter is too grungy:
- Your heating system won’t be able to stay on, or it may get too warm from limited airflow.
- Your energy expenses may go up because your heat is working too often.
- Your heater could fail sooner than it should because a filthy filter triggers it to work harder.
- Your heating can be cut off from power if an excessively dirty filter results in a tripped breaker.
Depending on what type of heater you own, your air filter will be inside the blower compartment of your furnace, an attached filter case or wall-mounted return air grille.
To replace your filter:
- Turn off your furnace.
- Take out the filter and hold it up to the light. If you can’t notice light through it, use a new one.
- Insert the new filter with the arrow facing toward the furnace 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 may have to replace your filter more frequently.
To make the process smoother down the road, use a permanent writing tool on your heating system exterior or ductwork to show the airflow direction and filter size.
4. Check the Condensate Pan
Commonly known as drain pans, condensate pans capture liquid your heating system removes from the air.
If liquid is seeping from your heater or its pan is overflowing, use these recommendations.
- If your pan has a drain (look for a PVC pipe), double-check that it isn’t full. If it needs to be drained, drop in a special pan-cleaning tablet you can get at home improvement or hardware retailers.
- If your pan has a pump, check the float switch. If the lever can’t be moved from the “up” position with standing water in the pan, contact us at 928-251-4327, because you will probably have to get a new pump.
5. Check for Heating Error Codes
If faults keep on happening, look within your heater’s plastic window to check the blower motor’s status. Depending on the brand, the light may also be attached on the exterior of your heating system.
If you notice anything except an uninterrupted, colored light or twinkling green light, contact us at 928-251-4327 for HVAC service. Your heater could be emitting an error code that is calling for specialized service.
6. Scrub the Flame Sensor
If your furnace makes an effort to start but turns off without blowing warm air, a filthy flame sensor might be at fault. When this happens, your furnace will attempt to turn on three times before a safety feature turns it off for about an hour.
If you feel comfortable with removing the panels from your heating system, gently scrubbing your flame sensor is work you can do yourself. Or, one of our heating service specialists has the ability to complete it for you.
If you are confident cleaning 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 fresh paper towel
As the next step:
- Disable the heater’s power through its wall switch or breaker. If your furnace’s gas valve isn’t electric, you will need to shut off the gas as well.
- Take off the heater’s front panel and track the wire to the flame sensor.
- Remove the rod and use your sandpaper, steel wool or emery cloth to gently scrub the metal rod.
- Clear the rod with a paper towel.
- Screw the sensor back in.
- Secure the furnace doors.
- Turn the furnace’s power back on. It could proceed through a set of inspections before continuing regular heating. If your furnace doesn’t turn on, the sensor might need to be replaced or something else may be creating an issue. If this occurs, get in touch with us at 928-251-4327 for heating and cooling repair assistance.
7. Reignite the Pilot Light
If you own an older heater, the pilot light could be extinguished. To relight it, locate the guide on a sheet on your heating system, or try these recommendations.
- Look for the switch on the bottom of your furnace labeled “pilot,” “on” and “off.”
- Turn the switch to the “off” position.
- Wait at least five minutes to prevent creating a fire.
- Push the knob to “pilot.”
- Push the “reset” lever as you bring the flame of a long lighter to the pilot light opening.
- Depress the “reset” lever once the pilot light is ignited.
If you have gone through the list twice and the pilot light still won’t light or remain ignited, call us at 928-251-4327 for furnace service.
Check Your Gas Supply
Try turning on an additional gas appliance. If it doesn’t work, your natural gas delivery may be turned off, or you could be out of propane.