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

Having a smart thermostat isn’t just wise for saving on heating costs. 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 let you know 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,” that means your furnace is short cycling. Short cycling is when the furnace turns on for a short period of time then switches off. This HVAC game of red light, green light stops your home from being warm 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 need to be replaced sooner.

Without Furnace Heads Up, you might not detect your furnace is turning on and off frequently, since its blower fan might keep running. This feature can detect 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.

Replace Your Air Filter Often

If your air filter is too dirty, it will restrict airflow. Your furnace will then shut off prematurely to prevent overheating. We encourage changing 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 fixes the problem.

• • Press the ring to pull 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. Hit “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 finished.

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 & Plumbing at 866-397-3787 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 is short cycling. You can determine if there’s a problem by watching your furnace as it turns on. Here’s what to look 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.

• • Turn 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 depends on 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 due to the fact it’s dirty or malfunctioning. Your furnace will then turn off as a safety precaution. If your furnace is short cycling, you’ll observe 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 coating of carbon on the surface. Cleaning a dirty flame sensor will stop the short cycling problem. This job 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 breaking 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 blocked by snow or bird nests, so you’ll want to ensure that it’s always clear. If the pipe gets blocked, 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 generally will stop 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 small amount is enough to trip the pressure switch. The uneven flow of air into and out of the system triggers 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 triggered.

An Expert HVAC technician from Service Experts Heating, Air Conditioning & Plumbing can look up the codes for you and determine the problem. Unfortunately, Nest has not evolved to the point where it can read 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 receive 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 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 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.