Nest Thermostat Cycling On and Off? Try These 11 Fixes

Can't Add Second Nest Thermostat to App

The Nest thermostat is a popular thermostat that people love. There’s a valid explanation behind this. It analyses your temperature preferences and develops an energy-efficient plan tailored to your needs and preferences. As a result of integrating geofencing with your phone, the Nest Learning Thermostat and Nest E can detect when you are at home or away from home and adjust their settings to save you even more money.

The Google Nest Thermostat represents a significant advancement over prior programmable thermostats powered by a mix of wire and AA batteries. It is equipped with a rechargeable lithium-ion battery and cabling to connect to Wi-Fi, power its digital display, and switch on your heating and cooling equipment. The Nest thermostat will have some troubles from time to time. Some users have reported that the Nest thermostats cycles on and off often, resulting in unpredictable temperature fluctuations.

Why is My Nest Thermostat Cycling On and Off?

We live in an era in which smartphones connect us to practically every part of our life — and it appears that there is no end in sight to this phenomenon. This technology revolution is also having an impact on the way we manage our home comfort levels. Consequently, the basic thermostat, an entire fixture in our houses for decades, has undergone tremendous evolution. Nest thermostats are known for being dependable gadgets. Various factors might create issues with them, but most are simple to fix. Some of the reasons the Nest thermostat cycles on and off are:

1. The Thermostat Could Be Faulty

You must ensure that your heating, ventilation, and air conditioning (HVAC) system is operating at peak performance to maintain comfort levels in your home or business space. While experiencing slight swings in the output of your HVAC system might be irritating, the problem can quickly escalate into an emergency if your equipment fails during periods of extreme weather when temperatures rise or drop.

You may suspect that something is wrong with your heating and cooling system, but if you have only recently installed the Nest, we recommend starting with your thermostat. It is crucial if the weather is mild and you haven’t been using your heat or air conditioning as regularly as you should have been doing. In addition to allowing you to monitor temperatures while you’re away, smart thermostats like the Nest are designed to make your life simpler with automated energy-efficient programming and the ability to check temperatures when you’re away from home. When yours doesn’t run properly, it may be a frustrating experience. If the thermostat cycles on and off, it could be because the thermostat itself is faulty.

2. Entire HVAC System Needs Maintenance

Because the Nest Thermostat is connected to the HVAC system, if there are problems with the HVAC system, there will be problems with the thermostat. The typical problem is that the Nest Thermostat does not draw enough electricity from the HVAC system in most situations. You will be able to determine whether the system requires maintenance or whether the thermostat in question causes the problem. To troubleshoot, do the following:

  1. Remove the furnace from the wall outlet by disconnecting it from the wall outlet.
  2. Disconnect your system from the mains power supply and turn it off.
  3. Remove your present thermostat from its mounting bracket on the wall.
  4. Connection of the second thermostat to the HVAC equipment and activation of the HVAC equipment
  5. If your other thermostat is also short cycling, it’s likely that your HVAC system is malfunctioning as well.

3. Direct Heat Source/Sunlight May Affect the Thermostat

In natural sunlight and high temperatures, the Nest thermostat is particularly sensitive. If the thermostat is in the path of a heat source or has direct sunshine shining on it, it will perceive that it is overheating and will shut down to protect itself. As a result, there will be continual cycles on and off. In addition, the temperature readings will be erroneous due to this. The Nest Thermostat is not correctly working because it has been subjected to excessive heat. It would be best to relocate your Nest away from direct sunshine and heat sources to resolve this problem. Additionally, inspect the wiring and the base of the Nest Thermostat to determine if there is any additional damage that requires repair.

4. Look Out for a Faulty/Damaged Fuse

When the Nest thermostat is overloaded, fuses are utilized to keep it from becoming damaged. A blown fuse is one of those things that you wouldn’t expect to impact the performance of a Nest thermostat. It’s an uncommon occurrence, but it does happen. When this occurs, the thermostat is unable to function correctly.

You’ll notice that the temperature fluctuates at random intervals or that the thermostat alternates between on and off. Cycling on and off is most often caused by a fuse that isn’t adequately secured in the fuse box. A blown fuse may cause a Nest thermostat that will not switch on at any time. To fix a blown fuse, you must first determine which fuse is causing the problem. After that, you’ll need to swap out the fuse for a new one.

5. The Batteries Are Old/Worn Out

Although the Nest Thermostat has an internal battery, its interface is powered by its C-wire. To keep the battery functioning properly, it must get replaced regularly. When the battery is low or completely depleted, the Nest Thermostat turns down without prior notice. In the event of a power loss, backup batteries are available. If one of the batteries in the Nest thermostat runs out of power, the thermostat will cycle on and off. It is necessary to replace the batteries to resolve the problem.

If the Nest Thermostat’s batteries are wearing out rapidly, it may appear that the thermostat is cycling on and off, but replacing the batteries is a simple repair. To change the batteries in the gadget, you must first unplug it from the power source. Then you’ll need to figure out where the old battery is. Last but not least, remove the old batteries from their sockets and replace them with two fresh batteries.

6. The Cables Aren’t Inserted Correctly

If you see the Nest Thermostat turning on and off repeatedly over some time, first check your wiring. Loose connections from old cables in the house may be at blame. Although the Nest Thermostat is designed to prevent it from using excessive energy from the power socket, improper wiring might lead the device to use a lot of electricity when charging its batteries. Your thermostat will not recharge appropriately as a result of this. It might eventually result in the thermostat’s batteries emptying too rapidly, necessitating restoring it more frequently.

7. Bugs and Software Issues

Nest thermostats, like other electrical devices, might experience software glitches and bugs from time to time, but this is nothing new. There will be a variety of outcomes depending on which bugs are present, including the thermostat cycling on and off. The cycle will affect the charging of the battery and will cause the battery to deplete more quickly than it should. These problems might occur due to a software upgrade that was either inadequate or erroneous. Because Google Nest is known for promptly addressing software flaws, future software upgrades for the Nest thermostat will likely address the issues. Regularly, you need manually update the Nest Thermostats software on your computer.

How to Fix Nest Thermostat Cycling On/Off

If the Nest Thermostat cycles on and off, you can troubleshoot the issue and try to fix it yourself. If you are not comfortable wiring or doing it yourself, you can call in the professionals. Some of the ways to improve a Nest that cycles on and off are to:

1. Make Sure All Wires Are Inserted Properly

It’s critical to ensure that all of the connections connected to the Nest thermostat are in proper working condition. The thermostat may cycle on and off if there are any difficulties. Remove the product handbook from the shelf and go over the connection instructions to determine which wire should be connected to which portal. It is how you may go about it:

  1. Find an illustration of the Nest wiring configuration that you may use as a reference to help you with the installation.
  2. Rename the Nest thermostat wires to correspond to the labels found in the handbook or guide that came with the thermostat.
  3. Remove the Nest’s LCD screen from the device.
  4. Wires should be disconnected and reconnected in line with the guide wires.

Once the wires are correctly inserted, the thermostat should no longer cycle on and off.

2. Change Batteries

Even though the Nest thermostat is not battery-powered, it does have a lithium-ion battery that serves as a backup in a power loss. If the Nest’s battery voltage falls below 3.6V, it will be unable to connect to your Wi-Fi network. Settings > Technical Info > Power may get found on the thermostat’s menu. The first figure you should see should be the voltage of the battery. If the voltage is more than 3.6, you’re in excellent shape. The voltage is low because there may be a wiring issue, and your Nest may not be charging correctly if this is the case. Having a Nest that isn’t correctly charging can affect the batteries, and you may need to change them (view on Amazon). To replace the batteries, follow these steps:

  1. Unmount the thermostat from its base.
  2. Remove the old batteries from the rear of the thermostat display and set them aside for later use.
  3. Insert the two new batteries into the battery compartment.
  4. Push the thermostat back into the base until it snaps back into place.

3. Remove Heat Source

Placing your thermostat close to a direct heat source can cause it to operate improperly. It would be best if you thought long and hard before deciding where you will place the thermostat. If you find that the Nest Thermostat short cycles and there is a heat source nearby, you need to remove the heat source. When it comes to determining the ideal location for a central heating thermostat, there are a few basic dos and don’ts to keep in mind that can impact the efficiency of your heating system. You want to locate it in the most convenient location feasible. Temperature swings that are frequently up and down could cause your thermostat to get confused, and your house will not achieve the appropriate temperature you’ve set. It might result in energy waste and comfort issues in your home.

4. Check If the HVAC System Needs Maintenance

The majority of homeowners don’t give their heating and cooling systems a second consideration until something goes wrong with them. A well-functioning heating, ventilation, and air conditioning (HVAC) system that is also energy efficient, on the other hand, necessitates the need for routine maintenance. Having your heating and cooling systems tuned up twice a year, once for heating and once for cooling, may help you enjoy superior interior comfort throughout the year.

Whether it’s been a while or you’ve never had your HVAC system serviced, there are a few signs to look for that signal it’s time to call in a professional to do preventative maintenance. One of the symptoms you need to get the Nest Thermostat serviced is if the thermometer cycles on and off.

5. Check System Compatibility

Your present thermostat’s wiring will need to be checked to see whether or not your system is Nest thermostat compatible and which Nest thermostat models it will function with. Usually, all you have to do is remove the cover from your thermostat and enter the wires you discover into the compatibility test. The Nest app and the Home app will also let you know if your system is compatible and provide you with a wiring schematic to help you complete the installation. The wire connections on a thermostat may have two labels, which can be confusing, or they may not have any tags. Sometimes, a wire is connected to the wrong thermostat connection, which might cause your system to malfunction in rare instances. In certain circumstances, you’ll need to look at the control board of your device to identify the cables.

6. Install A Common Wire

The C-Wire, sometimes known as the “common wire,” is responsible for providing a constant supply of 24 VAC electricity to the thermostat. In most cases, it is a wire that goes from your furnace to the thermostat (assuming you are fortunate enough to have one). C wires are required for any “smart” thermostat that must be linked to a power supply, regardless of whether your heat pump is electric or gas. The Nest Thermostat is designed to operate in most houses without using a C wire. However, a C wire or another appropriate power accessory for some systems will be required. Installing a new standard wire or repurposing an existing spare wire as the common wire are also options. If neither of these solutions is viable, an add-a-wire module will be considered as a possible solution.

A standard wire, often known as a C wire, is used to supply a constant power source to the Nest Thermostat, ensuring that the thermostat’s internal battery is constantly charged.

It is possible that if the Nest Thermostat is positioned close to your HVAC system, this will be a simple process because all you will need to do is install a new wire from the Nest Thermostat to your HVAC system. If, on the other hand, your HVAC system is not close to your thermostat, it will most likely be necessary for you to put a new wire through your walls to connect the HVAC system and the thermostat. The most straightforward solution for beginners and HVAC professionals with the least effort is using a Nest Thermostat Common Wire Transformer.

To install a standard wire:

1. Decide on the wire routing.

2. Use the methods that are available to you to run the wire. Pictures of the current connections on your HVAC system and your thermostat before you begin are recommended if you intend to draw the new wire by first taking out the old one.

3. Make sure that you tape the two wires together securely, but do not expand the profile of the wire or use so much tape that it becomes snagged in the process.

4. It is now necessary to rejoin the wires at your HVAC equipment, which you have done by pulling the cable.

5. Remove the lid and check for the circuit board underneath it. There will be many terminals labeled R, W, Y, G, and C on the circuit board, among other things.

6. You will now require the terminals in the same condition as before, and you will utilize the photograph you took to re-wire the proper HVAC terminals in their place. Directly, using the additional wire you placed, you will connect one of the wires to the C wire on the HVAC system, completing the circuit. Make a note of the color of the wire that you used to connect the C terminal in the furnace.

7. Now that the cable has been put on the system, it’s time to connect the Nest Thermostat to the HVAC system. The Nest Thermostat will be wired using the same color wires that you used to connect the furnace terminals to the furnace.

8. Now, connect the cable you used for the C wire on the HVAC system to the C terminal on the Nest Thermostat to complete the installation.

9. Now that you’ve completed the wire installation, you can replace the cover on the HVAC system and attach the Nest Thermostat to its base with the included screws. Reconnect the power to the HVAC system once it has been completed. Follow the Nest Thermostat’s setup menu instructions and click OK to check that the standard wire has been connected.

7. Align All Cables on Nest and Furnace

Short cycling refers to when the furnace will turn on for a few seconds, turn off for a few seconds, turn on again, turn off again, and so on. The most straightforward approach to determine whether or not the furnace is the source of the problem is to:

  1. Turn off the electricity in your furnace.
  2. Remove the Nest thermostat from its mounting bracket.
  3. Red (Rc) and White (W1) wires should disconnect from the thermostat.
  4. Use whatever method you have to transport those electrons to connect the Red and White wires.
  5. Restart your furnace by turning the electricity back on.

If the stove is fine, all you need to do is align the Nest and furnace cables. Most people install a standard wire.

8. Contact HVAC Specialist

Google advertises the ease with which its Nest thermostat devices may get installed. It is so simple that anyone can do it. A little understanding of DIY will allow homeowners to swiftly install the device and have it linked to the internet in under an hour. Even though this is correct, the truth is a little more complicated. Incorrect installation can damage the thermostat or cause problems in the long run, so it is always safe to have a specialist install the Nest for you. If the Nest Thermostat continues short cycling, your HVAC system may malfunction. To resolve this issue, you will need to contact an HVAC specialist who will do more testing on the system and determine the best solution.

10. Replace Your Nest Thermostat

Since replacing your Nest Thermostat is the fix you probably didn’t want to hear, if you’ve found that your Nest Thermostat is damaged and the problem is deeper since you’re unable to reset it, you’ll need to get it replaced. If you have experience with repairing your Nest Thermostat and you have the appropriate tools, you can get it repaired. If not, you’ll need to go to a repair store that can get your Nest Thermostat repaired.

If a repair store isn’t around, you can replace your Nest Thermostat (view on Amazon). If you’re on an old generation, upgrading to a new generation will lower the number of issues you have with your Nest Thermostat and you’ll no longer experience cycling issues if it’s being caused by a problem within your thermostat. The Nest Thermostat is relatively cheap and having one that functions properly is crucial for convenience around your home.

11. Contact Google

If you’ve tried all the fixes and for some reason, your Nest is still cycling offf and on, the last option is to contact Google for a fix. If you couldn’t fix it, it looks like there’s a deeper issue that needs to be diagnosed and fixed. You’ll need to enter your Nest Thermostat information, then you have the option to message them through their messaging system, call them, or request service so that they’ll fix your Nest Thermostat.

The Takeaway

The Nest Thermostat is a great smart thermostat that is reasonably priced. It has a sleek design that fits any home, and while it is simple to use, you can still run into issues with it. Most Nest owners report that the thermostat cycles on and off, but this article has given you fixes you can try to get the thermostat working correctly. If you do not want to cause any damage to the Nest, look for local HVAC specialists and have them take a look at the thermostat for you.

David Johnson is a freelance writer with 9 years of experience writing for Techzillo and other established tech outlets like iMore. His focus and key interests are Apple and accessibility as well as consumer technology in general. Read our Editorial Guidlines and Fact Checking process.


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