Why is My Furnace Not Working?

If you find yourself asking that question, you and your family are likely suffering in a cold and uncomfortable home at the moment. While you may be wondering if it’s time to call in a professional, there are a few simple troubleshooting tasks you can try first to see if you can resolve the problem on your own.

Tip #1: Check your thermostat.

This may seem obvious, but you’d be surprised how often a thermostat can inadvertently get turned to “OFF” or “COOL.” Look at your thermostat to be certain it’s set to “HEAT,” and to the desired temperature for your family. If you have a battery-powered thermostat, you may need to change the batteries.

Tip #2: Check your furnace filter.

If you can’t remember the last time you replaced your air filter, it may be full of dirt, dust, pet hair, etc. A clogged filter impedes air flow. This means that the warm air generated by your furnace can’t be efficiently pushed out through your home’s ducts. No warm air flow means you’re left with a cold home.

Tip #3: Reset your circuit breaker.

The circuit controlling your furnace may have been tripped. Check your circuit panel to see if the breaker for your furnace is “OFF.” If so, you will need to flip the breaker back and forth to reset it.

Tip #4: Check the safety switch on your furnace’s door.

Many heating systems come equipped with a safety switch that stops the furnace from cycling on if the access panel to the unit is not securely in place. When checking the safety switch, first shut off power to your furnace and then do a visual inspection of the unit, making sure all panels and doors are in place. If not, reset the door, and then turn the power back on to your unit.

Tip #5: Check your natural gas furnace’s flames.

If your furnace is running but not keeping your home warm, look at the flames within the unit the next time it cycles on. If the flames are blue, your burners are clean. If the flames seem uneven and yellow, this could be an indication that the burners are dirty. To clean them on your own, shut off all power and gas to the unit. Then use a vacuum to remove built-up dust around the blower and burners. Once cleaned, turn the power and gas to the furnace back on. If you are not comfortable turning off the gas to your system, contact a professional.

Tip #6: Check to be sure there are no obstructions to your system’s air flow.

Walk around to the different rooms of your home to be sure vents aren’t blocked by furniture, rugs, or curtains. When your vents are blocked, air from the furnace won’t make its way into your home to keep your family warm and toasty.

Tip #7: Check to see if there are areas of air loss around window and door frames.

This is another tip for families who have a furnace that still cycles on and off like normal but have a home that doesn’t feel very warm. Run your hand around window and door frames to see if you can feel cold air coming through. If you notice cold pockets, these are areas where warm air is escaping from your furnace (and where cold air is getting inside). To take care of the problem, add extra insulation, weatherstripping, or caulking around the window and door frames.

Still not sure what the problem is?

Contact a heating professional for additional assistance. A trained expert will be able to quickly diagnose and treat the problem so that your family isn’t left in the cold.