Furnace Not Working? Here Are the Top 10 Most Common Reasons for Furnace Failure.

It’s a common theme in life: things often stop working when we need them the most. This is especially true of furnaces in the winter! Once cool weather hits, we receive numerous calls about furnace problems. Fortunately, many of the most common furnace issues are easy to troubleshoot yourself. 

Here’s a list of the top 10 most common reasons for furnace failure:

Your Thermostat is Malfunctioning

One of the first things to check when your furnace stops working is that the thermostat is working properly. First, check that the thermostat is on. Next, check the setting and make sure it’s switched to heat. Even though this seems obvious, many service calls could be avoided by performing this simple check! 

Check the Breaker Box

If the thermostat is working correctly, the next thing to check is if any of the fuses have been blown. If not, check the unit to make sure the power switch is on. Lastly, it’s always a good idea to check that the front panel door on the furnace is latched. Many furnaces won’t engage if the door isn’t shut all the way. Or your furnace may use a simple wall switch to turn on.

Ignition Failure

If you’ve gone through steps 1-2 and it hasn’t solved the issue, check to see if your furnace is failing to ignite. The furnace won’t light if it’s having issues with the pilot light or electrical systems. To check the pilot light, you’ll need to open the burner chamber door and locate the pilot light tube. If the pilot light is working correctly, you should see a small flame. 

Blower Motor

If the blower motor has stopped working, it will prevent the furnace from being able to move the heat it generates throughout your home. To check the blower motor, turn on the furnace and switch the thermostat to “fan only.” Wait for a few minutes and see if you can hear the fan turn on. If you can, the blower motor isn’t the issue. If the fan doesn’t start, it’s time to get your blower motor serviced or replaced. 

Dirty Air Filters

Is it time to change your air filters? Dirty or clogged filters are a very common reason for furnaces to stop working, especially if you have a large family or a lot of pets. Filters help to clean the air that heads into the furnace, as well as the heated air sent from the furnace to the house. Dirty filters reduce the airflow, which can cause heat and pressure to build up within the furnace. The furnace may still run but with less heat output and reduced efficiency. Many newer furnaces can detect this and will often shut down before the filter can cause an issue. 

Blocked Ducts or Vents

Like dirty air filters, a blocked ventilation or duct system can block airflow to and from the furnace. To check whether this is the issue, start by turning on the heat. When the fan beings to blow, check the vents in each room to see if there’s any airflow. If there’s a noticeable lack of air blowing from a specific vent, the duct will probably need to be cleaned. Having your vents cleaned regularly will improve air quality and energy efficiency—and keep your furnace running well!

Air Leaks

If you’ve gone through steps 1-6 and determined everything is working as it should, then you could have an air leak in your system. If this is the case, you may find that your home stays a bit cool because the warm air is heading outside. Or, if there’s a draft, cold air could be coming inside your home. Checking the ventilation areas inside and outside your home can help you determine whether you have an air leak. 

Fuel Supply

All furnaces need fuel, although the type of fuel can vary based on the model. Many furnaces run on natural gas, but there are also electric and gas furnaces. If you have a natural gas furnace, make sure that the lines are working by checking other gas appliances in your home and that the gas valve is turned on. 

Blocked Drainage Hose

High-efficiency furnaces tend to drain a lot of water during the winter. Check your furnace’s drainage hose to see if any sediment or mold is causing a blockage. If you’re able to remove the dirty hose, give it a good flush to help clear the blockage. 

Lack of Maintenance

With our busy lives, it’s easy for routine maintenance to be put on the back burner. Unfortunately, if your furnace isn’t being maintained, it could develop a variety of issues that aren’t as common—or easy to fix—as the ones listed above. One easy way to ensure your HVAC system stays maintained is by taking advantage of our planned maintenance agreement. We’ll come to your home twice a year and perform routine cleaning and maintenance on your system. You also receive a 10% discount on any repairs, no after-hours charges, and priority service!

Need Assistance with Your Furnace? Contact the Experts at PECO!

If troubleshooting doesn’t resolve the problem, or you’re noticing strange smells or noises around your home, don’t hesitate to contact the experts at PECO Heating & Cooling! We’re always happy to help, especially when it comes to your family’s comfort in the winter. Call our 24/7 answering service at (864) 639-2424!