Solved: Nest Noticed Your Furnace Shuts Down Within 15 Minutes of Heating
Using a smart thermostat isn’t just smart for spending less on heating expenses. It can also let you know if there’s an issue with your furnace.
The Google Nest has a function called Furnace Heads Up, which will alert you if it notices an issue 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 why this is happening 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 switches on for a brief period of time then turns 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 deterioration on your furnace. It may also be more susceptible to breaking down and may even require replacement more quickly.
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 take place 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 Often
If your air filter is too dirty, it will restrict airflow. Your furnace will then shut down early to avoid overheating. We recommend replacing flat filters once a 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 getting 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 choose "settings" and then "equipment."
- The thermostat will show the wires connected to it. Select "continue."
- You’ll see system components shown. Select "test."
- Choose "Furnace Heads Up" and follow the instructions. Your furnace will go through a 15-minute heating check 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 help. 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 is short cycling. You can tell 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.
- 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 hear it turn on.
- The ignitor will begin 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 hot enough, the gas will switch on and the burners will light.
- If the flame sensor can’t sense 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 off after a couple of seconds.
If you’re questioning how flame sensors could get dirty being bathed in fire constantly, a blend 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 issue. This job is best left to an Expert. That's because 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 it needs to be replaced.
Check Your Furnace’s Exhaust Pipe Often
Your high-efficiency furnace vents combustion gases outside through a PVC pipe. This pipe can get clogged by snow or bird nests, so you’ll want to ensure that it’s always clear. If the pipe gets clogged, it can cause your furnace to overheat. It could also cause carbon monoxide to flow back into your home, creating a potentially life-threatening situation.
However, modern furnaces have a pressure switch that generally 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 a location that's accessible by tiny hands. Even this small amount is enough to trigger 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 encounter short cycling and a furnace error code specifying the pressure switch was triggered.
An Expert HVAC technician from Service Experts Heating & Air Conditioning 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 need 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, our Experts have the expertise 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 book your appointment, contact 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.