Why Does My Furnace Keep Shutting Off?
If your furnace is shutting off unexpectedly, it can be a major inconvenience. Not only will you have to call a technician to come to fix the problem, you’ll also be without heat during the cold winter months.
In this guide, we will discuss some of the most common reasons why furnaces keep shutting off. We will also provide tips on how to troubleshoot and fix the problem yourself.
Reasons Why Your Furnace Keeps Shutting Off
There are a few different reasons why your furnace may be shutting off prematurely. Here are some of the most common causes, and how to fix them:
Dirty air filter
One of the most common reasons for a furnace to shut off is a dirty air filter. If your air filter is clogged with dirt and dust, it will restrict airflow to the furnace. This can cause the furnace to overheat and shut off.
To fix this problem, simply replace the air filter with a new one. You should also check your air filter monthly, and replace it as needed.
Closed vents
If you have any vents in your home that are closed, this can also cause your furnace to shut off. That’s because the furnace needs proper airflow to function properly. When airflow is restricted, the furnace will overheat and shut down.
To fix this problem, simply open any closed vents in your home. You should also make sure that there are no objects blocking the vents.
Thermostat problems
Another common reason for a furnace to shut off is that there’s a problem with the thermostat. If your thermostat is not working properly, it can cause the furnace to turn off prematurely. There are a few different ways to troubleshoot this problem:
First, make sure that the batteries in your thermostat are fresh. If the batteries are low or dead, this can cause the furnace to turn off.
Next, check the thermostat settings. Make sure that the thermostat is set to “heat” mode, and that the temperature is set above the current room temperature. If you’re still having problems, you may need to replace the thermostat.
Furnace switch
Another potential problem is the furnace switch. If the switch is turned off, the furnace will not operate. Make sure that the switch is in the “on” position.
If you’re still having problems with your furnace, it’s best to call a technician. They will be able to diagnose and fix the problem quickly.
Your furnace is overheating
If your furnace is overheating, it will automatically shut off to prevent any damage. This can be caused by a number of different things, such as a dirty filter or a blocked vent.
To fix this problem, you’ll need to clean or replace your furnace filter, and make sure that all vents are clear of debris. You may also need to have your furnace serviced by a professional.
Your furnace is not getting enough power
If your furnace is not getting enough power, it will also shut off. This can be caused by a tripped circuit breaker, or a blown fuse.
To fix this problem, you’ll need to check your circuit breaker or fuse box. If the circuit breaker has been tripped, simply reset it and try again. If the fuse has blown, you’ll need to replace it with a new one.
Your furnace is not properly vented
If your furnace is not properly vented, it can also cause the furnace to shut off. This is because, as stated earlier, the furnace needs proper ventilation to function properly.
To fix this problem, you’ll need to have your venting system checked by a professional. They will be able to determine if there are any blockages or leaks in the system.
Oversized furnace
If your furnace is too big for your home, it will also cause the furnace to shut off. This is because the furnace will cycle on and off more frequently, which can lead to overheating.
To fix this problem, you’ll need to have a professional come out and size your furnace. They will be able to determine the correct size for your home, and install it properly.
The flame sensor is soot-covered
If your furnace keeps shutting off, one possible reason is that the flame sensor is soot-covered. The purpose of the flame sensor is to detect whether or not there is a flame present. If the sensor is soot-covered, it may be unable to detect the presence of a flame, and as a result, the furnace will shut off.
To clean the dirty flame sensor, you’ll need to remove it from the furnace and use a wire brush to remove the soot. Once you’ve cleaned the sensor, reattach it to the furnace and see if that solves the problem. If not, you may need to replace the sensor.
What are Some Tips For Maintaining Your Furnace?
Even if your furnace is brand new, it’s important to take care of it. Here are some tips for maintaining your furnace:
Change your furnace filter regularly
A dirty furnace filter will make your furnace work harder, and less efficiently. Change it every month, or more often if you have pets or live in a dusty area.
Have your furnace serviced regularly
A qualified technician can spot potential problems before they become big ones. Have your furnace serviced at least once a year, and more often if you have an older furnace.
Don’t close vents in unused rooms
Closing the vents in unused rooms might seem like a good way to save energy, but it can actually damage your furnace. When you close vents, it throws off the balance of air pressure in your home, which can put stress on your furnace and shorten its lifespan.
Be careful when using space heaters
Space heaters can be a fire hazard, and they can also put stress on your furnace. If you must use a space heater, make sure to turn off your furnace and keep the space heater in a safe place.
By following these tips, you can help extend the lifespan of your furnace, and keep your home safe and comfortable.
Tips on How to Troubleshoot and Repair Your Furnace
If your furnace keeps shutting off, it may be due to a variety of the aforementioned reasons, or a combination of them. Here are some tips on how to troubleshoot and repair your furnace:
First, check the thermostat to make sure it is set to “heat” mode and not “cool” or “off.” If the thermostat is set properly, check the furnace’s circuit breaker or fuse to make sure it has not tripped. If the circuit breaker or fuse is fine, then the problem may lie with the furnace itself.
If you have a gas furnace, check to see if the pilot light is lit. If not, follow the instructions in your furnace’s manual to relight it. If the pilot light is lit, but the furnace still won’t turn on, the problem may be with the furnace’s gas valve. Check to see if the valve is open. If it is, turn it to the “off” position and then back to “on.”
If your furnace still doesn’t turn on after having performed these troubleshooting steps, call a qualified furnace repair technician to diagnose and repair the problem.
Is it Bad For Your Furnace to Short Cycle?
The answer is, unfortunately, yes. When your furnace repeatedly shuts off and turns back on, it’s called short cycling. This can be extremely detrimental to both the lifespan of your furnace, and your energy bill. Here’s why:
- Short cycling puts unnecessary wear and tear on your furnace - Every time your furnace starts up, there is stress on the system. This wear and tear can shorten the lifespan of your furnace.
- Short cycling wastes energy - Every time your furnace turns on, it uses a burst of energy. When it short cycles, it's using that burst of energy over and over again needlessly. That wasted energy not only raises your energy bill, but also increases your carbon footprint.
Frequently Asked Questions
1
Does a heat exchanger leak cause the furnace to shut off?
A heat exchanger leak can cause your furnace to shut off because it’s a safety feature designed to prevent your furnace from overheating. When the heat exchanger starts to leak, it means that there is a hole in it. This hole can allow harmful gasses to escape into your home.
2
Is the furnace the same as a heating system?
No, the furnace is not the same as a heating system. A heating system includes all of the components that are necessary to heat your home, such as the furnace, ductwork, thermostat, and more.
3
Can a dirty blower wheel cause the furnace to shut off?
Yes, a dirty blower wheel can cause your furnace to shut off because it can cause the furnace to overheat. Dirty air filters can also cause the blower wheel to become dirty. When the blower wheel is dirty, it doesn’t work as efficiently, and can cause your furnace to overheat.
The furnace is an essential part of your home in winter, so when it starts acting up, it’s important to get to the bottom of the problem as soon as possible.
If your furnace keeps shutting off, there could be a number of potential causes. However, with a little investigation and some basic troubleshooting, you should be able to identify and fix the problem yourself. If you aren’t confident that you can handle these issues yourself, you can always contact a professional to diagnose the situation, and fix the issue for you.