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

Having a smart thermostat isn’t just wise for spending less 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 an issue 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 common 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 see 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 short period of time then turns off. This HVAC game of red light, green light stops 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 require replacement sooner.

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

How Do I Keep My Furnace from Short Cycling?

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

Change Your Air Filter Often

If your air filter is too dirty, it will limit airflow. Your furnace will then shut off prematurely to avoid overheating. We recommend replacing flat filters once a month, and pleated filters every three months. It’s easy to stay on top of changing 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 choose “settings” and then “equipment.”

• • The thermostat will show the wires linked to it. Choose “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 test and tell 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, contact 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 explanation why your furnace is short cycling. You can determine if there’s a problem by paying attention to your furnace as it starts up. Here’s what to check for.

• • Take off 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 higher indoor temperature.

• • When you switch 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 warm enough, the gas will turn 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 turn 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 wondering how flame sensors could get dirty being bathed in fire constantly, 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 problem. This task is best left to an Expert. That’s because 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 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 cause your furnace to overheat. It could also cause carbon monoxide to flow back into your home, creating a potentially deadly situation.

However, modern furnaces have a pressure switch that typically will prevent these situations from happening. Families with small children will often find their kids have stuffed toy cars, sticks or nuts into the exhaust if it’s in a location 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 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 & Plumbing can look up the codes for you and diagnose the problem. Unfortunately, Nest has not evolved to the point where it can read the error codes furnace manufacturers create, so you will still require a pro to help you out.

Let the Experts Solve 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 knowledge to fix 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 request 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.