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

Using a smart thermostat isn’t just wise for spending less on heating costs. It can also let you know if there’s a problem with your furnace. 

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

One of the most common issues 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 switches on for a brief period of time then turns off. This HVAC game of red light, green light prevents your home from being warm and can increase your energy bill. It can also increase deterioration on your furnace. It may also be more susceptible to breaking down and may even need to be replaced more quickly. 

Without Furnace Heads Up, you might not notice your furnace is turning on and off often, since its blower fan might keep running. 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 simple ways you can prevent your furnace from short cycling. 

Replace Your Air Filter Regularly 

If your air filter is too dirty, it will limit airflow. Your furnace will then shut off early to avoid overheating. We encourage changing flat filters every month, and pleated filters every three months. It’s simple to stay on top of changing your filter by adding 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 fixes the problem. 

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

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

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

Clean or Replace Your Furnace’s Flame Sensor 

Having a dirty or bad flame sensor is another top explanation why your furnace might short cycle. You can determine if there’s a problem by paying attention to your furnace as it turns on. Here’s what to check for. 

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

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

If you’re questioning 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 issue. This task 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 outdoors 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 plugged, it can result in your furnace overheating. It could also result in carbon monoxide flowing back into your home, creating a potentially deadly situation. 

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

An Expert HVAC technician from Service Experts Heating & Air Conditioning can look up the codes for you and determine the problem. Unfortunately, Nest has not developed to the point where it can interpret the error codes furnace manufacturers produce, so you will still require a pro to assist you. 

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 resolve 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, call 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.