Using a smart thermostat isn’t just smart for saving on heating costs. It can also alert you if there’s an issue with your furnace.
The Google Nest has a function called Furnace Heads Up, which will alert you if it senses a problem with your heating system. You’ll see the warning 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 brief period of time then turns off. This HVAC game of red light, green light prevents 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 susceptible to breaking down and may even need to be replaced more quickly.
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 pick up on 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 restrict airflow. Your furnace will then shut down early to prevent overheating. We recommend 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 getting a Furnace Heads Up alert, you can run a test to see if that repairs the problem.
- Press the ring to pull up the Quick View menu, where you’ll select "settings" and then "equipment."
- The thermostat will display the wires linked to it. Choose "continue."
- You’ll see system components displayed. 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 finished.
Google says if the filter is clean or if your furnace didn’t clear the test, something else could be wrong that requires professional assistance. If this happens, contact Boehmers/Cronin Emery Home Services by Enercare at 519-804-1617 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 is short cycling. You can determine if there’s a problem by paying attention to your furnace as it turns on. Here’s what to check 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.
- Switch on the furnace by setting the thermostat to a warmer indoor temperature.
- When you switch on the heat, the fan will begin running 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 detect a flame, it’s usually because it’s dirty or malfunctioning. Your furnace will then shut 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 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 job is best left to an Expert. That's due to the fact an HVAC professional like Boehmers/Cronin Emery Home Services by Enercare 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 blocked 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 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 young children will often find their kids have jammed toy cars, sticks or nuts into the exhaust if it’s in a location that can be reached by tiny hands. Even this little amount is enough to trigger the pressure switch. The irregular flow of air into and out of the system trips 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 Boehmers/Cronin Emery Home Services by Enercare can check the codes for you and diagnose the problem. Unfortunately, Nest has not developed 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 Solve 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 Boehmers/Cronin Emery Home Services by Enercare, our Experts have the knowledge to fix 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 519-804-1617 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.