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

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

The Google Nest is equipped with a function called Furnace Heads Up, which will alert you if it notices an issue 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 typical issues is: “Nest noticed that your furnace shuts down within 15 minutes of heating.” Here’s why this is happening and how you can fix it.

Your Furnace is Short Cycling

When you see the message “Nest noticed that your furnace shuts down within 15 minutes of heating,” that means your furnace is short cycling. Short cycling is when the furnace turns on for a short period of time then turns off. This HVAC game of red light, green light prevents your home from heating up and can increase your energy bill. It can also increase wear and tear on your furnace. It may also be more susceptible to breaking down and may even require replacement sooner.

Without Furnace Heads Up, you might not detect your furnace is turning on and off often, because its blower fan might keep running. This feature can recognize power interruptions that take place during short cycling.

How Do I Keep My Furnace from Short Cycling?

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

Change Your Air Filter Regularly

If your air filter is too dirty, it will limit airflow. Your furnace will then shut off prematurely to avoid overheating. We encourage changing flat filters every month, and pleated filters every three months. It’s easy to stay on top of replacing your filter by setting up a Filter Reminder on your thermostat.

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

  • Push the ring to bring up the Quick View menu, where you’ll select "settings" and then "equipment."
  • The thermostat will display the wires connected to it. Choose "continue."
  • You’ll see system components shown. Select "test."
  • Select "Furnace Heads Up" and follow the instructions. Your furnace will go through a 15-minute heating test 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 awry that needs professional assistance. If this happens, contact Golden Seal Service Experts at 630-246-2698 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 tell if there’s a problem by paying attention to your furnace as it starts up. Here’s what to check for.

  • Remove the door from your furnace so you can look at 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 start 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 hot enough, the gas will switch on and the burners will light.
  • If the flame sensor can’t detect a flame, it’s usually due to the fact it’s dirty or defective. 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 couple of seconds.

If you’re wondering how flame sensors could get dirty being bathed in fire continuously, a blend 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 job is best left to an Expert. That's due to the fact an HVAC professional like Golden Seal Service Experts will be able to clean it without breaking it or be able to tell you if it needs to be replaced.

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 blocked, it can result in your furnace overheating. It could also result in carbon monoxide flowing back into your home, creating a potentially fatal situation.

However, modern furnaces have a pressure switch that typically will stop these situations from occurring. Families 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 tiny hands. Even this small amount is enough to trigger the pressure switch. The irregular flow of air into and out of the system triggers the pressure switch, which shuts off the burners. If this is the root of your problem, you will encounter short cycling and a furnace error code specifying the pressure switch was tripped.

An Expert HVAC technician from Golden Seal Service Experts can check the codes for you and determine the problem. Unfortunately, Nest has not developed to the point where it can read 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 Golden Seal Service Experts, our Experts have the knowledge 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 630-246-2698 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.

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