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

Having a smart thermostat isn’t just wise 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 function called Furnace Heads Up, which will alert you if it notices a problem with your heating system. You’ll see the alert on the thermostat, in the app and in your monthly Nest Home report.

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

Your Furnace is Short Cycling

When you get 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 switches on for a brief period of time then turns off. This HVAC game of red light, green light stops 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 notice your furnace is turning on and off often, because its blower fan might keep going. This feature can pick up on power interruptions that occur 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 Regularly

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

If you’ve changed 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 select “settings” and then “equipment.”

• • The thermostat will show the wires connected to it. Select “continue.”

• • You’ll see system components shown. Hit “test.”

• • Choose “Furnace Heads Up” and follow the instructions. Your furnace will run a 15-minute heating check and give you the results when it’s finished.

Google says if the filter is clean or if your furnace didn’t clear the test, something else could be wrong that needs professional help. If this happens, call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for furnace repair.

Clean or Replace Your Furnace’s Flame Sensor

Having a dirty or malfunctioning flame sensor is another top reason why your furnace might short cycle. You can tell 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 look at 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 warmer indoor temperature.

• • When you turn on the heat, the fan will turn on 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 ignite.

• • If the flame sensor can’t detect a flame, it’s usually because it’s dirty or defective. Your furnace will then shut off as a safety precaution. If your furnace is short cycling, you’ll notice the flame and fan shutting down after a couple of 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 job is best left to an Expert. That’s due to the fact an HVAC professional like Service Experts Heating, Air Conditioning & Plumbing will be able to clean it without damaging it or be able to tell you if it needs to be replaced.

Check Your Furnace’s Exhaust Pipe Often

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 cause your furnace to overheat. It could also cause carbon monoxide to flow back into your home, creating a potentially fatal situation.

However, modern furnaces are equipped with a pressure switch that generally will prevent 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 tiny hands. Even this little amount is enough to trigger the pressure switch. The uneven flow of air into and out of the system triggers the pressure switch, which shuts off the burners. If this is the underlying cause of your problem, you will encounter short cycling and a furnace error code indicating the pressure switch was triggered.

An Expert HVAC technician from Service Experts Heating, Air Conditioning & Plumbing 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 & Plumbing, our Experts have the expertise to resolve any furnace problem quickly and affordably. What’s even better is that we stand behind our repairs with a 100% Satisfaction Guarantee for one year.* To book your appointment, contact us at 866-397-3787 or schedule online.

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*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.