How to Troubleshoot a Home Furnace


furnaceIn today’s modern technological age it seems more people understand how to change a smartphone’s SIM card or replace computer memory than how to fix household appliances. This is a shame, because while it’s important to keep up with the times, certain fundamentals of what keeps a home in good working order aren’t likely to change anytime soon.

Take the furnace for example. It’s one of the most vital appliances in the home – especially during those chilly winter months — and most people don’t go within a few feet of it out of fear of the unknown. Oftentimes when a furnace breaks down the first thing people do is call a repair person and pass the buck to him or her. The interesting thing is there is a lot of money to be saved by fixing a furnace issue on one’s own.

This doesn’t require comprehensive knowledge of the ins and outs of gas furnace systems; just a keen eye for troubleshooting.


Believe it or not, just like a car a dirty furnace filter can cause the whole unit to shut down. The good news is this is a relatively quick fix. Simply locate the access panel on the outside of the furnace. Most modern furnaces will have a slot or pullout drawer above, below, or to the side of the access panel. Simply pull the drawer out or slide the rectangular filter out of its slot. Inspect the filter for signs of dust, dirt or gunk build-up. If the filter is caked over with dirt and dust then it is time for a replacement.


The panel door is used to protect the blower motor, and many furnaces simply won’t function if the door is loose or ajar. Check the door to ensure it is latched firmly in place. There’s no need to spend over $100 on a technician when the only thing plaguing the furnace is a loose panel.


It’s not a huge secret that a furnace won’t be effective in the home without a secure supply of gas. To this end it’s important to check the gas supply lines that run to the furnace and ensure the connections are solid and the gas valves are on the “on” position.


If the above tips yield no success, check to ensure the furnace is receiving a proper supply of power. There may be an actual furnace switch – appearing much like a standard light switch – next to the furnace unit. Check to ensure this switch is in the “on” position. If this fails, and if confidence isn’t a factor, check the breaker box in the home to ensure power is being routed to the furnace unit. Those in newer residences should find a diagram on the breaker box panel detailing which breakers are routed which appliances. Ensure the furnace breaker switch is in the “on” position.


If all else fails then it’s time to check the furnace thermostat and ensure the settings are correct. These many furnaces have modern thermostats with digital readouts that make discerning the problem a breeze. For example, there may be a warning prompt on screen detailing the exact nature of the problem. Also, sometimes the problem is as simple as low batteries for the thermostat.

These are just a few ways to troubleshoot a home furnace that should get the unit back up and running in no time. Of course if these methods fail to produce results, then it may be time to bite the bullet and shell out for a pro.

Kiersten Gurry is a freelance writer in Flagstaff, Arizona. She writes on a wide variety of topics in the home improvement for First Impression Security Doors. She is very knowledgeable about security doors and iron gates in particular.

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