Solved: Nest Noticed Your Furnace Shuts Down Within 15 Minutes of Heating 

Using a smart thermostat isn’t just smart for saving on heating expenses. It can also let you know if there’s an issue with your furnace. 

The Google Nest is equipped with a feature called Furnace Heads Up, which will alert you if it notices a problem with your heating system. You’ll notice the warning on the thermostat, in the app and in your monthly Nest Home report. 

One of the most typical problems is: “Nest noticed that your furnace shuts down within 15 minutes of heating.” Here’s what’s doing on and how you can fix it. 

Your Furnace is Short Cycling 

When you get the message “Nest noticed that your furnace shuts down within 15 minutes of heating,” it’s saying your furnace is short cycling. Short cycling is when the furnace turns on for a brief period of time then turns off. This HVAC game of red light, green light prevents your home from heating up and can drive up your energy bill. It can also increase wear and tear on your furnace. It may also be more likely to break down and may even need to be replaced sooner. 

Without Furnace Heads Up, you might not detect your furnace is turning on and off often, since its blower fan might keep going. This feature can pick up on power interruptions that happen during short cycling. 

How Do I Keep My Furnace from Short Cycling? 

There are a few easy ways you can keep your furnace from short cycling. 

Change Your Air Filter Often 

If your air filter is too dirty, it will restrict airflow. Your furnace will then shut down early to prevent overheating. We recommend changing flat filters every month, and pleated filters every three months. It’s simple to stay on top of replacing your filter by setting up a Filter Reminder on your thermostat. 

If you’ve replaced your filter after receiving a Furnace Heads Up alert, you can do a test to see if that repairs the problem. 

• Press the ring to bring up the Quick View menu, where you’ll choose “settings” and then “equipment.” 

• The thermostat will display the wires linked to it. Select “continue.” 
• You’ll see system components shown. Select “test.” 
• Select “Furnace Heads Up” and follow the instructions. Your furnace will run a 15-minute heating check and give you the results when it’s done. 

Google says if the filter is clean or if your furnace didn’t pass the test, something else could be wrong that needs professional assistance. If this happens, call Service Experts Heating & Air Conditioning at 954-736-4314 for furnace repair. 

Clean or Replace Your Furnace’s Flame Sensor 

Having a dirty or malfunctioning flame sensor is another top explanation why your furnace might short cycle. You can determine if there’s a problem by watching your furnace as it starts up. Here’s what to check for. 

• Remove the door from your furnace so you can see the burners. If you have a viewport in the furnace door, you may not need to remove the door for this. 
• Switch on the furnace by setting the thermostat to a higher indoor temperature. 
• When you switch on the heat, the fan will begin running first. You should notice it turn on. 
• The ignitor will start to glow. The ignitor is either on the left or right of the burners, but it depends on the furnace model. 

• Once the ignitor is warm enough, the gas will turn on and the burners will light. 
• If the flame sensor can’t sense a flame, it’s usually because it’s dirty or defective. Your furnace will then shut off as a safety measure. If your furnace is short cycling, you’ll observe the flame and fan shutting off after a few seconds. 

If you’re wondering how flame sensors could get dirty being bathed in fire continuously, a combination of moisture and chemicals in the air form a thin layer of carbon on the surface. Cleaning a dirty flame sensor will end the short cycling problem. This job is best left to an Expert. That’s due to the fact an HVAC professional like Service Experts Heating & Air Conditioning will be able to clean it without breaking it or be able to tell you if you need a new one. 

Check Your Furnace’s Exhaust Pipe Frequently 

Your high-efficiency furnace vents combustion gases outside through a PVC pipe. This pipe can get obstructed by snow or bird nests, so you’ll want to ensure that it’s always clear. If the pipe gets clogged, it can cause your furnace to overheat. It could also cause carbon monoxide to flow back into your home, creating a potentially life-threatening situation. 

However, modern furnaces are equipped with a pressure switch that typically will stop these situations from happening. Households with young children will often find their kids have jammed toy cars, sticks or nuts into the exhaust if it’s in an area that can be reached by little hands. Even this little amount is enough to trip the pressure switch. The irregular flow of air into and out of the system trips the pressure switch, which shuts down the burners. If this is the root of your problem, you will experience short cycling and a furnace error code indicating the pressure switch was tripped. 

An Expert HVAC technician from Service Experts Heating & Air Conditioning can check the codes for you and diagnose the problem. Unfortunately, Nest has not evolved to the point where it can interpret the error codes furnace manufacturers produce, so you will still require a pro to help you out. 

Let the Experts Handle Your Short Cycling Furnace 

If you get the message, “Nest noticed that your furnace shuts down within 15 minutes of heating,” you know what to do. At Service Experts Heating & Air Conditioning, our Experts have the expertise to fix any furnace problem quickly and affordably. What’s even better is that we back our repairs with a 100% Satisfaction Guarantee for one year.* To request your appointment, contact us at 954-736-4314 or schedule online. 

*Not applicable to the Advantage Program. See your signed Advantage Program Agreement for full details and exclusions. 100% Satisfaction Guarantee is subject to certain restrictions and limitations as set forth in the applicable Terms and Conditions.