Uh-oh… your furnace has stopped working all of a sudden and it isn’t coming back on anytime soon.
What can you possibly do? Why did it stop working in the first place?
Truth be told, there are many reasons why it could’ve stopped working, and it’ll take some diagnosing to figure out the reason why.
Here’s a list of typical furnace problems and which one might be causing your furnace to stop working so suddenly.
Common Furnace Problems
Unfortunately, everyone is a victim of a furnace suddenly stopping at some point in their lives.
Perhaps these usual problems are the reason for your sudden stoppage.
Filthy Filter
Have you ever thought back to the last time you replaced your filter and realized it’s been more than several months?
If so, that could be the main reason your furnace is shot.
At some point, filters get covered with so much dirt and filth that it clogs the airflow in your system.
That causes your furnace to work overtime to try and push the required amount of air through.
In this case, your dirty filter has either caused your furnace to work too hard or it broke the limit switch in the fan.
Wrong Sized Furnace
Furnaces come in all different shapes and sizes. That way, they can fit the proper size into the area size it needs to cover.
Should a furnace be installed that’s too small for the area, it will be forced to work especially hard to try and compensate.
That, much like a clogged filter, will lead to it overheating and shutting off.
Issues With the Thermostat
There are occasions where the furnace isn’t properly working due to the thermostat.
If a programmable thermostat hasn’t been switched over to “heat” since you last put it on “air” back when spring/summer started, that could be the leading cause of why your furnace isn’t on.
Essentially, your furnace is only “not working” because the thermostat is telling it not to.
Switching the thermostat to “heat” should turn the furnace back on rather quickly if this is the reason it’s off.
Faulty Circuit Breaker
For those that are unfamiliar, the circuit breaker is a device that’s relied on to automatically stop and protect an electrical circuit from harming machines in use (such as your furnace).
Should the circuit breaker attached to the furnace become compromised, the furnace would’ve turned off.
Try to find the circuit switch (looks similar to a light switch) and turn it back on.
If nothing happens after a few minutes there may be a bigger problem at play such as a blown fuse.
Issues with the Ignition
There are two different types of ignitions that can be used on a furnace.
The hot surface ignition system waits for “the sign” from the thermostat. Once it’s given the green light the ignition is heated up by electrical currents.
The standing pilot gas furnace, which is much less common in modern furnaces, is a continuously burning flame that’s used to ignite the primary gas burner.
If you have a hot surface ignition, there could be any number of problems that have caused it to stop working. It’s better to get it looked at by a trained professional to diagnose the issue.
Should you have a standing pilot gas furnace, it may be as simple as relighting the flame if it’s gone out.
Gas Leak
If you’ve noticed the smell of gas every once in a while after your furnace stopped working, that’s an indication there’s a gas leak.
Know that this problem needs to be taken care of immediately by a professional.
It’s safest to evacuate you and your family from the house until it’s fixed.
If you can, go over to your gas meter, and try to find the gas inlet pipe. If you’re able to find it, use a wrench and rotate the valve a quarter of the way.
That will turn off the gas supply for an expert to come in and take a look.
Vicious “On” and “Off” Cycle
If you’ve noticed that your furnace is repeatedly turning off and back on at an alarming rate, you’ll want to inspect the thermostat.
The heat anticipator in the thermostat may have been accidentally switched away from the “longer” setting, causing shorter cycles.
Try placing the switch close to “longer” and wait about half a day to try and notice any differences.
If that didn’t work, it may be time to switch out thermostats OR it may be a sign of your furnace being overheated.
Broken Belt
If you can still hear the furnace running, but are noticing that there isn’t any air blowing out, the belt may have broken.
All you’ll need to do is replace it by turning off the entire unit AND the gas (as mentioned earlier).
Find a small door compartment and open it, search for where the belt is located.
If you’re comfortable, purchase a new belt with the same specifications as the one currently attached and switch out the two.
Get an Expert’s Opinion!
Regardless of what furnace problems you’re having, it’s always safer to call an expert.
The last thing you want to do is damage the furnace further!
Be sure to read this article on tips to get your furnace ready for winter. There you’ll find a few more pointers on how to properly prepare for the colder months.
For more inquiries, please reach out by phone at 610-258-0201.
